Liquid degas system

ABSTRACT

A medical ultrasound system. A base unit is included having system electronics, a user interface and ultrasound control electronics. An ultrasound therapy head is in electronic communication with the base unit. The therapy head includes a replaceable, sealed transducer cartridge with a coupling fluid therein. A cooling system is provided for cooling the coupling fluid. A plurality of guide indicators are positioned around the therapy head to align with crossed lines on a patient so as to properly align the therapy head prior to use. The therapy head can provide variable treatments to an area while the therapy head is in contact with a patient.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims priority of U.S. patent application Ser.No. 61/246,937, filed Sep. 29, 2009, the full disclosure of which isincorporated herein by reference.

BACKGROUND

High intensity focused ultrasound (HIFU) has gained increased popularityand support as a therapy device in the medical community. Ultrasoundenergy has been used extensively in non-therapeutic procedures such astissue imaging for diagnostic purposes. HIFU involves higher levels ofpower (over diagnostic ultrasound), to achieve a variety of physicaleffects in tissue for the purpose of achieving a desired therapeuticeffect. A recurring design issue for HIFU treatment devices is balancingthe needs of the therapeutic demands a procedure may require, and theacceptability of the device produced by medical device manufacturers.This is particularly true in aesthetic medicine, where devices oftherapeutic utility must meet the rigorous utility, image and usabilitydemands of practitioners of aesthetic medicine and their clientele.

BRIEF SUMMARY

Water and other liquids used in the methods and system for the presentinvention will frequently need to have dissolved gasses removed toproduce a degassed liquid stream. A liquid degas system suitable forproducing such a water or other liquid degassed stream comprises areservoir and a ventilation chamber within the reservoir, where thereservoir contains a gassed liquid which is subjected to a pressure dropsufficient to separate the gassed liquid into a degassed liquid streamand a gas stream which are then delivered to the ventilation chamber.Within the ventilation chamber, the gas and degassed liquid areseparated with the gas being returned to the gassed liquid within thereservoir and the degassed liquid being removed for use in the therapysystems herein, either as a cooling liquid, an acoustic coupling liquid,or both.

The liquid degas system further comprises a conduit located to receivethe gassed liquid from the reservoir and pass the liquid to a bottom ofthe ventilation chamber. The conduit has a flow restriction, such as areduced diameter orifice, valve, or other reduced diameter componentwithin the conduit which creates the pressure drop as the gassed liquidpresses through the flow restrictor. A pump is provided to cause thegassed liquid to flow from the reservoir, through the flow restriction,and through the conduit into the ventilation chamber. Typically, thepump will be positioned downstream from the flow orifice, usuallybetween the flow orifice and the ventilation chamber. A gas vent isprovided on the top of the ventilation chamber and receives theseparated gas and releases said gas through an exit port into the gassedliquid within the reservoir, typically at a level which is below the topof the ventilation chamber. An outlet is provided at the bottom of theventilation chamber to allow the degassed liquid to be removed from theventilation chamber and delivered to other parts of the system.

In exemplary embodiments, the system further comprises a distributionmanifold within the ventilation chamber, where the manifold receives thedegassed liquid and gas mixture from the conduit and distributes thatmixture throughout the ventilation chamber. Usually, the distributionmanifold includes sidewalls and a top with orifices formed therethroughto distribute and release the mixture within the ventilation chamber.The gas vent typically comprises a vent conduit attached at one end toan aperture for passage within the top of the ventilation chamber andhaving the exit port at a level below the top of the ventilationchamber. The characteristics of the pump and the sizes of the conduitand flow restrictor will be selected to provide a pressure drop acrossthe flow restrictor so that the liquid gas mixture has an absolutepressure in the range from 1 to 2.5 pounds per square inch (psi) afterit is passed through the flow restrictor. In the exemplary embodiments,the liquid degas system may be provided in an enclosure which isattached or otherwise coupled to an ultrasound therapy head by a cablehaving proximal distal ends. The cable provides liquid circuit from theoutlet of the degas system. Optionally, the system may include a chilleror cooler if the degassed liquid is intended to provide cooling for thetherapy head.

In another aspect of the present invention, a method for degassing aliquid comprising maintaining a gassed liquid in the reservoir. Thegassed liquid is drawn from the reservoir through a flow restrictor toform a mixture of degassed liquid and gas as a result of the pressuredrop which occurs as the liquid flow through the flow restrictor. Themixture of degassed liquid and gas is then passed to a ventilationchamber within the reservoir where the mixture is able to separate intoa gas portion which rises to the top of the chamber and a degassedliquid portion which falls to the bottom of the chamber. The gas isvented from the top of the ventilation chamber into the gassed liquid inthe reservoir, and the degassed liquid portion can be removed from thebottom of the ventilation chamber for use in the therapy systems of thepresent invention or in other systems.

This method may further comprise circulating the degassed liquid fromthe bottom of the ventilation chamber through a liquid circuit where itabsorbs gas and returns to the gassed liquid within the reservoir forrecycling and treatment. The liquid circuit may comprise a therapy headhaving an ultrasonic transducer therein, in which case the liquidcircuit may further comprise a heat exchanger to cool the degassedliquid before it enters the therapy head. In certain embodiments, themixture of the degassed liquid and gas maybe passed through adistribution manifold having a plurality of orifices which create apositive pressure and restrict flow of the degassed liquid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a medical ultrasound system of the prior art;

FIG. 2 is a perspective view of a medical ultrasound system inaccordance with an embodiment;

FIG. 3 is a perspective view of a medical ultrasound system inaccordance with an embodiment;

FIG. 4 is a front view of the base unit from FIG. 2;

FIG. 5 is a side view of the base unit from FIG. 2;

FIG. 6 is a interior perspective view of the main compartment accordingto an embodiment;

FIG. 7 is a interior profile view of the main compartment according toan embodiment;

FIG. 8 is a perspective view of the main compartment with coveraccording to an embodiment;

FIG. 9 shows a cross-section of a system for separating gas from agas-containing liquid in accordance with an embodiment.

FIG. 10A illustrates the operation of the degassing system of FIG. 9.

FIG. 10B illustrates an alternative embodiment of a degas system.

FIG. 11 is a schematic diagram illustrating a system for separating gasfrom a gas-containing liquid in accordance with another embodiment.

FIG. 12 is a block diagram of a medical ultrasound system having adegassing unit in accordance with an embodiment.

FIG. 13 is a cross section of a cable according to an embodiment;

FIG. 14 is a perspective view of the treatment head according to anembodiment;

FIG. 15 is a perspective view of the treatment head according to anembodiment;

FIG. 16 is a transparent profile view with internal components of thetreatment head according to an embodiment;

FIG. 17 is a transparent perspective view of FIG. 16;

FIG. 18 is a bottom isometric view of the therapy head of FIG. 15;

FIG. 19 is a schematic diagram representing some components of a medicalultrasound system in accordance with an embodiment;

FIG. 20 is a schematic diagram representing some components of a medicalultrasound system in accordance with an embodiment;

FIG. 21 is a perspective view of a lower compartment, or cartridge, forthe therapy head of FIG. 16 in accordance with an embodiment;

FIG. 22 is an exploded perspective view of the lower compartment of FIG.21;

FIG. 23 an exploded perspective view of a thermoelectric device stackand related components for the therapy head of FIG. 22;

FIG. 24 is a perspective view of the upper and lower compartmentthermoelectric device stacks;

FIG. 25 is a perspective view of the combined thermoelectric devicestack;

FIG. 26 is a perspective view of the exploded components of FIG. 21;

FIG. 27A is a schematic diagram representing components of a medicalultrasound system in accordance with another embodiment;

FIG. 27B is an isometric view of the bottom of the upper section inaccordance with an embodiment.

FIG. 28 is an isometric view of a transducer cartridge for a therapyhead in accordance with an embodiment;

FIG. 29A is an exploded isometric view of the transducer cartridge ofFIG. 28;

FIG. 29B is an isometric view of a bottom portion of a transducercartridge displaying an alternative fluid conduit in accordance with anembodiment;

FIG. 30 is an exploded isometric view of the transducer cartridge havinga thermal regulating device according to an embodiment;

FIG. 31 is an exploded isometric view of the transducer cartridgeaccording to an embodiment;

FIGS. 32A-B provide a pressure relief mechanism in accordance with anembodiment for the cartridge;

FIGS. 33A-B provide a pressure relief mechanism in accordance with anembodiment for the cartridge;

FIG. 34 illustrates the vacuum assembly of FIG. 9;

FIG. 35 shows an alternative embodiment of an interface cable;

FIG. 36A shows a tall stack transducer assembly;

FIGS. 36B-D provide views of a short stack transducer assembly,according to embodiments.

FIG. 37 shows a unigrip handle according to an embodiment.

FIG. 38 is a block diagram of a coupling fluid system, in accordancewith an embodiment.

FIG. 39 shows a medical ultrasound system having a coupling fluidreservoir and a coupling fluid line, in accordance with an embodiment.

FIG. 40 is a block diagram of fluid flow system, in accordance with anembodiment.

FIG. 41 is a transparent side view of a treatment head having a spraynozzle according to an embodiment.

FIG. 42 is a perspective view of an ultrasound head having handles andspray nozzles coupled with the handles, in accordance with anembodiment.

FIG. 43 is a perspective view of an ultrasound head having offset spraynozzles, in accordance with an embodiment.

FIG. 44A is a perspective view of an ultrasound head having integratedspray nozzles, in accordance with an embodiment.

FIG. 44B provides a view of an ultrasound therapy head having a guidecomponent for the liquid dispersal device(s) according to an embodiment;

FIG. 45 is an illustration of a template for use in creating a variablesize and alignment pattern on a patient body according to an embodiment.

FIG. 46 is an illustration of the use of a variable treatment sizepattern in an embodiment.

FIG. 47 is an illustration of the use of a variable treatment alignmentpattern according to an embodiment.

FIG. 48 illustrates a simplified block diagram of a computer system inaccordance with embodiments.

FIG. 49 schematically illustrates a series of modules according to anembodiment.

FIG. 50 is an example of a touch screen.

FIG. 51 shows steps for providing treatment information to a controlmodule in accordance with embodiments.

FIG. 52 illustrates a module for providing variable treatment todifferent areas in accordance with embodiments.

FIG. 53 shows an arrangement of broadcast zones divided into treatmentand non-treatment zones.

FIG. 54 shows steps for establishing a partial treatment area inaccordance with embodiments.

FIG. 55 shows a method for partial site treatment in accordance withembodiments.

FIG. 56 shows a method for providing selective treatment at a site inaccordance with embodiments.

FIG. 57 shows another method of selective treatment at a therapy headsite in accordance with embodiments.

DETAILED DESCRIPTION

In the following description, various embodiments of the presentinvention will be described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practicedwithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed.

Described herein are medical ultrasound systems for body contouring,components of medical ultrasound systems, and methods for servicing,updating and using medical ultrasound systems.

Medical ultrasound systems on the invention typically include two maincomponents with various subcomponents. The first main component is thebase unit. The base unit component is usually a mobile piece ofequipment designed to rest on the floor and provide an enclosed formfactor that houses numerous subcomponents of the system. Details of thesub components are provided throughout the description. Mainly, thesubcomponents that are either large or heavy, or more convenientlylocated away from a patient, are stored in the system base. The baseunit refers to the larger of the two main components. It may havecastors or wheels and be referred to herein as a cart. Mobility in thebase unit is generally provided for ease of use, but in no way should beread as limiting the invention in any way.

The second main component is the treatment head. The treatment headcomponent of medical ultrasound systems of the invention is alsodescribed herein in various embodiments. In a typical aspect, thetreatment head has two sections that are detachable from each other.When the two sections are properly assembled in such aspects, thetreatment head operates in conjunction with the base unit to produceultrasound energy for medical purposes. Each section is often referredto herein as the therapy head body, and the cartridge. Alternatively thetherapy head body may be the upper compartment while the cartridge isthe lower compartment. The therapy head (or therapy head body) containssubcomponents that are designed for long wear and extended use. Thecartridge contains subcomponents that are generally designed for limiteduse before being replaced. The term treatment head and therapy head aresometimes used interchangeably and may include the cartridge with theupper compartment. The cartridge contains an energy emitter, and in mostembodiments, this energy emitter may be at least one high intensityfocused ultrasound (HIFU) transducer. The cartridge generally isremovable and has a limited life span.

The primary purpose of the system is to provide therapeutic ultrasoundfor the purposes of body contouring. This intended use of the system isfor non-invasive therapy. That is, the present system and its many subcomponents are designed for use outside a patient body and typicallydoes not involve any minimally invasive techniques, surgery, or tissueimaging other than what the system is capable of performing by itself.The system can operate independently of diagnostic, imaging, oranesthetic equipment that might also be used on a patient. Systems ofthe invention also or alternatively can be used in a non-sterile field.Sterilization of the many parts and system surfaces is not typicallyrequired between uses, though individual users may choose to do so forvarious reasons. The many embodiments of the invention described hereinprovide for a more usable device for body contouring over those of theprior art.

An interface cable is typically used to connect the base to thetreatment head. A number of examples of such cables are describedherein.

The description of the many embodiments of each of the components is notmeant to imply a strict requirement of one embodiment of one componentbeing tied solely to another embodiment of another component. Rather thedescription of the various embodiments of each the base unit, thetreatment head and the interface cable should be viewed asinterchangeable. An embodiment of the base unit may be used with morethan one embodiment of the treatment head, and vice versa. Someembodiments of either the base or the treatment head will logicallyexclude embodiments of the other component. Those skilled in the artwill realize certain pairings of base unit and treatment head do not gotogether, however in general the various embodiments of one componentare designed to work equally well with the various embodiments of theother components. The various embodiments are herein described both intext, and in annotated drawing descriptions.

In an embodiment, the base unit is a base with a low center of gravityand rests on a frame with casters. Extending from the base is, e.g., acombined ergonomic front panel and main system compartment. The mainsystem compartment can be mounted on the frame with casters, and theergonomic front panel serves as one side of the compartment. The frontpanel typically extends upward from the base and main compartment. Oneor two handles are usually integrated into the front face so that thehandle(s) can be easily reached, and a display screen is commonlyergonomically positioned for easy viewing. The front panel typicallyfurther possesses at least one docking port for removably receiving atreatment head. Additional docking ports may also be incorporated intothe front panel.

Extending from the upper end of the front panel typically is a displayscreen. The display may also be a touch screen interface. The displaypanel or the base unit may have speakers for producing audible signalsfor the user. Inputs for other user interface devices, such as akeyboard, mouse or pointer device, may also be provided.

The main compartment of the base unit contains the bulk of the systemelectronics. These electronics typically include a group of treatmenthead connectors (electrical and fluidics) and a treatment head interfaceboard; a digital data interface; system electronics including a therapyprocessor and a high voltage transmitter; electronic control for afluidics system (liquid circulation system) having chiller/fans, fluidtank, pump and sensors; and a system power supply. The fluidics systemmay also incorporate a degas device for removing dissolved gasses fromthe liquid. Additional electronics may be added via one or more daughterboard adapters located on any one of the existing boards within thesystem.

Systems of the invention should typically utilize liquid in the fluidicssystem in a different manner over the prior art. Instead of filling anddraining the therapy head when replacing a transducer, many embodimentsuse a transducer in a sealed cartridge. The cartridge may contain about100 to 200 milliliters (ml) of static liquid coupling fluid, whereas theprior art may use about 400-500 ml of liquid routed throughout the baseunit and the therapy head. The cartridge may be designed for using about120-160 ml, and in another aspect the cartridge may contain 130-150 ml.In addition, embodiments herein utilize a cartridge that is selfcontained. Thus, the coupling liquid remains static in the cartridge,and does not need to be replaced when that cartridge is removed from thetherapy head. Distinguished from the coupling liquid is a cooling liquidin many embodiments. The cooling fluid is circulated through a heatexchanger thermally connected to the cartridge. The heat exchanger maybe in the cartridge (integrated within the cartridge) or part of thetherapy head and fashioned to draw heat away from the cartridge. Using aseparate cooling liquid (from the coupling fluid) allows the coolingliquid circulation to move the length of the circulation system moreefficiently. The majority of embodiments also provide for a treatmenthead that no longer requires constant filling and draining, thusreducing the spillage and fluid loss from the fluidics system.Advantages of some embodiments of the systems of the invention also oralternatively include faster and/or cleaner replacement of thetransducer assembly.

The description of pressures herein make reference to either “absolute”pressure, or “gauge” pressure, both measured in PSI. Absolute pressureis the pressure measured independent of atmospheric pressure. It is the“absolute” pressure relative to zero PSI (pounds per square inch). Thegauge pressure is the pressure above the local atmospheric pressure.Gauge is the local atmospheric pressure, plus the pressure read in thesystem or component described. The various pressure readings are usuallycalled out, however unless specified, pressures relating to the therapyhead are generally GAUGE pressures, and pressures in the fluidcirculation components in the base are generally ABSOLUTE pressures.

The use of a separate cooling liquid and circulation system (separatedfrom the coupling liquid in the cartridge) may allow the circulationsystem to pump smaller volumes of cooling liquid to cool the cartridge.Typically, the cooling system pumps the cooling liquid at about 40 PSI(gauge) in the base unit to achieve a therapy head/cartridge systempressure of about 20 PSI (gauge). The cooling system pressure isgenerally above atmospheric pressure through out the system, but mayapproach atmospheric pressure when returning from the therapy head tothe fluid reservoir (described herein). In these embodiments, the lowerfluid quantity required in the therapy head allows for a lower volume offluid to be pumped, and may in turn allow for a pump using less power.It may also be true that a lower fluid flow rate (volume/sec) isrequired to provide the same level of cooling as in prior art systems.This feature provides another area of bulk and weight savings allowingthe present system to be substantially smaller in size and weightcompared to the prior art. Furthermore, the fluidics system in someembodiments no longer requires a degas unit for removing dissolved gasesfrom the coupling liquid as are used in prior art devices that circulatea coupling liquid around the transducer. This provides the advantage ofallowing the system liquid to contain dissolved gasses without causinginterference in the transmission of ultrasound energy in the cartridgefluid from the treatment head to the patient.

The system described herein typically makes use of higher levels ofintegration in the functions provided reducing power and electricalsignal interconnects between the various functions allowing for reducednumber of circuit cards and cabling internal to the system compared tothe prior art system shown in FIG. 1.

The system may have an Ethernet adapter to receive a 10/100/1000Ethernet line which may be used to link the system to a service computeror the internet, and provide software updates, system diagnosticcapabilities, account usage updating and/or investment recovery bankingof unused pay-per-use units for the treatment head (also known as “usersites” and described in co-pending U.S. patent application Ser. No.12/407,212, filed Mar. 19, 2009, and entitled “Methods and Apparatus forMedical Device Investment Recovery”).

The display screen typically included with the system provides systeminformation and operational information to the user. In one aspect, thedisplay has touch screen capabilities, allowing the user to use thescreen as a control interface for operating the system, checking systemstatus, running diagnostics programs, displaying error messages andsystem alerts, and/or providing a user with an interface to checknon-active functions related to system usage, such as checking the usersite bank account. The display screen may incorporate both button touchscreen functions, and motion sensitivity, similar to screens used inpersonal data assistants and mobile phones. It may also or alternativelyprovide an on/off switch and/or house a speaker. In another aspect, thescreen is a conventional LCD device.

One or more foot switch jacks can also or alternatively are provided forconnecting a single or multifunction foot switch. The foot switch mayoptionally be used to control therapy activation of the system. Someusers prefer hand activated therapy treatment while others prefer usinga foot switch. Typically, systems of the invention can provide theoption for either method to be used.

A system power supply is usually provided in the cart. In one aspect,the power supply can run on normal amperage and voltage. For example, inthe United States, the system operates on a standard 115 volt/15 amp 60Hz line using a grounded plug. In Europe the system operates on aEuropean standard 240 volts/50 Hz line. Similarly the system uses apower supply that converts the power of the local standard into thepower requirements the system needs for proper operation. A safetysensor or watchdog circuit monitors the AC power input as well as the DCoutput of the supply and provides a cut off in the event the power inputor output is out of safety specification for the system. In anembodiment, the system operates with as many components as possiblerequiring the same voltage. In another embodiment, the system utilizesone voltage for all components. In still another embodiment the systemutilizes two voltages for all components.

The system may have one or more treatment heads connected to the baseunit. The treatment head(s) are usually connected to the base unit by acable. In one aspect, the system has been partitioned to allow for aninterface cable to be used, which combines electrical and fluid channelsbetween the base unit and the treatment head. The treatment head mayalso or alternatively possess any of the following: user controlsallowing for the turning on or off of the transducer, a display toprovide status information, a speaker or sound emitting component ordevice, and/or any other controls and indicator lights as may bedesired. In addition to controls on the treatment head, display, and/orfoot switch, the base unit can have inputs for other user input deviceslike a keyboard, mouse (computer pointer device), or other control unit.A wireless control device may also be used.

In one aspect, the treatment head is connected to the base unit usingonly the minimum number of connections required for system operation.The proper functional partitioning of the system can allow for areduction in wires used to connect between the system electronics in thebase, and the treatment head. A technical challenge in the prior art wasthe requirement for multiple signals wires to be used for the interfacebetween the treatment head and system. By proper partitioning andcircuit design the interface for control, monitor and status can becomea pure digital interface. A digital interface can then be implementedusing serialization techniques to reduce the interface to a few digitallines. Serializing data allows for reducing the number of signalingcircuits. Another technical challenge of the prior art is providing alight weight and easily manageable cooling device for the hand heldcomponent. Reducing the cooling requirements of the cartridge can alsoallow the reduction of the fluid lines to and from the treatment head toallow for a small diameter interface cable.

To facilitate the removal of a mechanical arm as used in the prior art,one embodiment may partition the circuitry between the treatment headand base unit to allow for an interface cable to be used. An embodimentof an interface cable is now described. The interface cable possesses ahigh speed serial digital interface. The digital interface is enabled bypartitioning any power amplifiers, for motor control or cooling devicesfor example in the treatment head; digitizing analog signals in thetreatment head, for example temperature sensors, provide for a digitalinterface to the various functions in the treatment head and provide fora serial interface to the digital interfaces. This type of system allowsthe leveraging of existing Low Voltage Differential Signaling (LVDS)technology to implement a high speed serial digital interface betweenthe base and treatment head. The serial digital interface removes thebulk of analog, motor drive and parallel digital signals that werecarried on multiple cables in the prior art. By using high speed serialdigital interface, and properly partitioning the circuitry between thetreatment head and cart, the control and information can now be passedthrough a small group of twisted pair wires.

Serialization of the signals between the base unit and the treatmenthead is processed by a pair of chips; one in the base unit and one inthe upper compartment of the treatment head. The chips are responsiblefor regulating signal traffic produced by the system electronics (bothin the base and in the treatment head) and feeding them serially throughtwo pairs of twisted pair wires. One pair allows for uninterruptedsignal from the base to the treatment head, while the other pair allowsfor signal from the treatment head to the cart. The twisted pair wiresconnect (allowing electronic communication between) the pair of chipswhere encoding, decoding, and serialization occurs. The chips may begeneral processors, field programmable gate arrays (FPGA) or applicationspecific integrated circuits (ASIC) or any combination of these devicesand/or their equivalents. These chips can also perform additionalencoding for line balancing and bandwidth reduction. The chips may alsoprovide error checking of data.

In an embodiment, signal count can be reduced by using aserialize-deserialize routine executed between the pair of chips, onelocated in the base unit and the other in the treatment head. In anembodiment, a pair of field programmable gate array (FPGA) chips in thesystem and the head do additional encoding for line balance andtransmission line bandwidth reduction similar to 8B/10B encoding. TheFPGAs also error check the data. The pair of chips operate asserializer-deserializer (SERDES) components. The first chip in the baseunit receives electrical signals from the electronic components withinthe base unit. All the electrical components within the base unit thatare used to control any component, process or monitor any function inthe treatment head are routed through the first chip in the base unit.Data is transmitted between the base and treatment head chips using timedivision multiplexing. Thus where unserialized signal control wouldordinarily require at least one wire for every control circuit to theappropriate electrical control element to be controlled, variousembodiments of system of the invention allow signals to be sent tovarious components to be controlled over the same wire. In anembodiment, the serialize action takes 15 signals and encodes them to 18signals for transmission line bandwidth reduction as well as errorchecking The serializer then sends them through the first pair of wireswith the first signal being sent for a short period and then the secondsignal being sent for a short period, and so on. There are 20 timeperiods in all due to the overhead of a start bit and a stop bitsurrounding each set of 18 bits. All of this is controlled by the FPGAchips used in the SERDES operation (and/or an application specificintegrated circuit (ASIC) or equivalent function SERDES device). Thenumber of time periods is not fixed, and may be adjusted higher or loweras desired. Because the transmission and SERDES operation occur veryquickly relative to the mechanical operation of the treatment head,there is no issue of lag or signal backlogging in communication betweenthe base unit and treatment head during therapy treatment. By way ofexample, an embodiment of the above described operation takes advantageof simultaneous (parallel) system inputs that are sent to the treatmenthead in a serial fashion—or at least at a different level than the 15bits discussed above. Data that is low enough in bandwidth is serializedprior to sending. An example of this can be motor commands. In anembodiment, each of the two motors require 12 bits of drive command.This would mean that more than all of the 15 signaled bits would be usedup for just motor drive commands—24 bits. For this reason the systemassigns 4 of the lines to be a Serial Peripheral Interface (SPI) bus.The system sends all 15 bits 30,000,000 times per second, easilyenabling some of them to be serial in nature and still have a very highbandwidth compared to the requirements. The 24-bit data on the SPI busin the above example would send the two drive commands about 625,000times a second. This is well above the 20 kH motor current commandsample rate produced by the motor servo controller in the main unit. Ittakes at least 48 “frames” to transmit the 24 bits in a serial fashionalong with a data clock for SPI operation—a frame being one group of 15bits of parallel.

By using a first pair of wires to transmit electrical signals from thebase unit to the treatment head, and a second pair of wires to receiveelectrical signals from the treatment head (transmitted from thetreatment head to the base unit) two electrical signal paths may operatesimultaneously, with each path operating through a SERDES pathway. Inaddition to the control of various electronic components through theSERDES pathway, the operation of an array transducer can be handled inreal time using direct wire connect between the transducer beam former(in the base unit) and the individual elements of an array transducer inthe treatment head as described above. This is achievable using the sameinterface cable because the control signals thusly serialized leaveplenty of room in the cable for many thin coax cables to drive an arraytransducer. If a single element transducer is used, only one coax cableis required, but several can be used to share the high power driverequirements or to optimize impedance matching. Appropriately, the cablecan be laid out for the number of coax, twisted pair, power/ground andfluid lines required to provide proper connection, command and controlof the treatment head.

Power is supplied from the base unit to the treatment head throughindividual power wires based on voltage needed to drive each component.To the extent multiple components in the treatment head can be driven bypower of the same voltage, those components can be placed in a circuitwith a single power wire carrying the appropriate voltage. The powerwire between the base unit and the treatment head may be insulatedand/or shielded so as not to produce any cross talk (signalinterference) with the electrical signal in the SERDES pathway. In anaspect, the power lines may not be shielded, but instead the lines maybe filtered at each end so as to just receive the direct current (DC).Alternatively, the data pairs are twisted and shielded to protect themfrom the power supply wires.

Integrated fluidics lines are also incorporated into the interfacecable. Using any of several cooling and fluid circulation systemdescribed herein, the need for large volume fluid flow is now reduced toa level where a smaller volume of fluid can achieve the resultspreviously required. This allows the use of reduced diameter tubescontributing to shrinking the design over the prior art.

In addition, the interface cable may include one or more transducerdrive carrying cables. These drive cables may be coax cables, twistedpairs or shielded wires. Shielding is generally used on transducer drivecables to provide shielding for electro-magnetic interference (EMI)reasons. In an embodiment, an annular array transducer may be used,where multiple drive cables (such as coax) may be used in the interfacecable to deliver signal to an array transducer. The number of coaxcables may correspond directly to the number of transducer elements, orthey may be reduced to fit a modified transducer excitement program(such as grouping elements into excitement groups, controlled by asingle time delay for further reducing the signal load). In anotheraspect of the system of the invention, an array transducer may be usedhaving twelve (12) to twenty four (24) elements, and the interface cablewould have a corresponding number of coaxial cables incorporated intoit. Alternatively the coaxial cables may be substituted with shieldedtwisted pairs (or unshielded wires if the bandwidth is low enough).

In an embodiment the interface cable has both 24 v and 5 v power wires,and a common ground wire. The various electronic elements in thetreatment head, such as motors, sensors, transducer and other componentscan all be driven directly (or converted to the desired voltage in thetreatment head) from the two power lines, one twisted pair (the othertransmits data back to the components in the cart), and however manycoax cables are required to drive the transducer in real time.Alternatively the components in the treatment head may all operate onone voltage (or converted to one voltage) and thus need only one powerline in the interface cable.

In addition to the components described herein as commonly incorporatedinto the interface cable, the cable itself may be connectorized. Thatis, the cable may be removably engaged to the system (and/or thetreatment head) to allow modularity of the treatment head to the system.In some cases the modularity will provide a means for attaching acompletely different cable between the treatment head and the base unit.In other embodiments, the interface cable may carry the appropriateelectrical communication and fluid requirements of different treatmentheads, so that only the treatment head need be removed from theinterface cable to allow connection of a new treatment head. Thisembodiment can allow a user to detach a therapy head from the interfacecable instead of removing the interface cable from the base unit,although the user may also elect to switch the interface cable with thetherapy head. The removable engagement of the interface cable typicallyadapts to both the electrical and fluid systems while maintaining acommon adapter among the different types of cables that can be used. Inone aspect, the system electronics can identify what kind of cable isattached to the base unit, and utilize the wire and fluid channels ofthe wire appropriately. This may be achieved by using a readableidentification chip incorporated into the interface cable or itsremovable engagement.

Automatic identification of the parts in the treatment head may occur byusing a query between the base unit and the treatment head where thequery produces a response code corresponding to a look up table storedin the base unit. The look up code provides the voltage and signalrequirements for the operation of the treatment head components. If theinterface cable is also replaced with the treatment head, a similarquery and response system can be used to identify the parameters of thecable. In addition to the cable or treatment head having an identifierresponse to a query, each individual electronic component within thetreatment head may respond to a query through the return twisted pair. Acombination of query and response systems may be used to ensure propercalibration of power, signal and control of the treatment head. In anembodiment the treatment head has an encrypted code to ensure the systemuses only authorized manufactured parts with the system. The lowercompartment can have (or be associated with) an encrypted authorizationcode to track both the proper use of authorized manufactured parts, andto track the use of the transducer for site banking purposes (and alsoused for calibration data). Further to the challenge and responsesystems described herein, the treatment head and lower compartment mayalso use a challenge and response protocol to ensure the treatment headand lower compartment of the treatment head are hooked up to a dulyauthorized cart. The challenge and use protocol and the site bankingprotocol are further described in co-pending U.S. patent applicationSer. No. 12/407212, mentioned above.

In operation, the user typically can hold the treatment head during aHIFU procedure, and the interface cable will allow greater mobility andfreedom to the operator to use the treatment head in virtually any angleor position over the prior art. The interface cable may be draped acrossthe body of the patient under treatment, or allowed to drape over thepatient's side.

If the use of a cable guide is desired by the user, an optional boom orcable retraction system may be used. A boom would provide a light weightalternative to a mechanical arm and provide sufficient structure tosuspend the interface cable so the interface cable makes its approach tothe patient from above the patient, instead of being draped across thepatient's body. A retraction device, like a spring tensioned reel, mayoptionally be included that provides cable management so the interfacecable does not get tangled up with the operator or patient. A retractionsystem may also be used within the base unit so when the treatment headis returned to its dock, the cable is automatically reeled in.Alternatively the guide may take the form of a boom, allowing theinterface cable to be projected horizontally over the patient. A boomcan be either retractable into the cart, or completely removable. Theboom could alternatively take the form of a light weight load balancingarm.

The treatment head typically operates as a single unit during therapy,but can be separated into two discrete subcomponents. The uppercompartment or therapy head body (body) usually contains electricmotors, control electronics, gears and linkages for moving a transducerassembly located in a cartridge as well as the electronics like motordrivers, DACs (digital to analog converters), ADCs (analog to digitalconverters) and/or other logic devices. The upper compartment istypically designed for extended use, and has components that are longerin wear, or relatively expensive to replace.

The cartridge may be referred to as the lower compartment. A coolingdevice is typically used to remove heat from the cartridge. A coolingdevice may remove heat from the cartridge in a number of differentfashions. In one aspect, a fluid circulation system in the base unitcirculates fluid into the treatment head to cool the cartridge. Thermalregulation of the cartridge can be important because the transducerassembly inside the cartridge may generate a significant amount of heat,which can adversely affect the reliability of the transducer in thecartridge and/or become uncomfortably hot next to a patient's skin. Whenthe therapy head body is connected to the cartridge, the treatment headis whole. The cartridge comes in multiple embodiments, and the uppercompartment comes in various embodiments to adapt to the cartridge.Alternatively, the cartridge comes in multiple configurations to adaptto various shapes and design embodiments of the therapy head body. Inone aspect, the cartridge is disposable.

The various descriptions for the cartridges are generallyinterchangeable. Typically these include several common features suchas: designed to be removably engaged to the upper section or therapyhead body. The cartridge defines an ultrasound chamber that contains anultrasound transducer. The chamber is typically a sealed enclosure thatis generally liquid tight. Although the chamber is often describedherein as being fluid filled or liquid filled with a coupling fluid, itis not necessary that the sealed fluid enclosure contain any particularfluid, but instead fluid is not leaked when put into the sealed fluidenclosure (ultrasound chamber). In several embodiments, one of severalfluids are selected as being used as the coupling fluid, and these areaspects of the invention (being “dry” or not liquid filled,alternatively being “wet” when one or more of the selected liquids isused in the ultrasound chamber).

The use of the term “ultrasound chamber” should not be interpreted aslimiting the scope of the disclosure to ultrasound energy being strictlyconfined to the chamber. The chamber is where the ultrasound transducerresides, with the specific intent in most embodiments that ultrasoundenergy will radiate out of the chamber when the device is in operation.The cartridge interior defines the ultrasound chamber, which is also asealed enclosure that is generally fluid tight.

In an embodiment, the transducer assembly is typically contained in asealed enclosure filled with an appropriate ultrasound coupling medium,such as degassed water. The enclosure may be water tight. The enclosuremay be made of plastic or other suitable material, and may have a liningon the interior of the compartment to prevent gas from seeping into thesealed enclosure and entering the degassed water. The lining can be, forexample, a sputtered metal layer, such as titanium. The enclosure has anacoustic window in all embodiments, which allows for an acoustic beampath for the transmission of ultrasound energy from the enclosedtransducer to outside the cartridge. In embodiments that may use ametallization layer or sputtered metal lining, the acoustic window mayalso be treated with such metallization or sputtered metal lining. Themetallization layer or sputtered metal material would form a thin enoughlayer so as to permit the transmission of ultrasound energy from thecartridge. The transducer assembly is mounted to a mechanical arm orlinkage that is able to engage a counterpart in the upper compartment.The upper compartment has an actuator assembly that moves the transducerassembly in the sealed enclosure by engaging directly (or indirectly) acontrol arm attached to the transducer assembly. The cartridge usuallyhas a fluid tight interface built into that portion of the cartridgethat engages the control arm extending down from the upper compartment.When the upper and lower compartments are properly connected, thecontrol arm from the upper compartment engages a receptacle in the fluidtight interface. The interface may be a spherical ball with an O-ringseal under pressure, a boot or other equivalent structure. When thecontrol arm of the upper compartment is moved by the actuator assembly,the transducer assembly in the lower compartment moves in a predictablefashion. The system controls the movement of the transducer assembly bycontrolling the motion of the control arm.

Electrical connections are usually provided either through the controlarm (as in a hollow arm with electrical signal paths running throughthere), or through a separate electrical plug/socket in the interfacebetween the upper and lower compartments. The electrical interfacebetween the upper and lower compartments may be within the confines ofthe physical volume where the two compartments are joined together, orit may be an electrical plug/socket interface outside the confines ofthe mechanical connection. The electrical interface can provide powerand timing control to the transducer assembly to control the acousticoutput, as well as power one or more of a variety of sensor elements inthe lower compartment that may be used to measure fluid temperature,pressure, dissolved gases and/or movement of the transducer assemblyduring a procedure.

In an embodiment, the cartridge can be sealed, so that a liquid withinthe cartridge is degassed. A metallization layer can help prevent gasleakage into the cartridge. Since the cartridge can be sealed, any heatbuild up in the cartridge may pose problems for the operation of thetreatment head, and/or be uncomfortable to either the user and/orpatient. If heat accumulation occurs, cooling the cartridge may benecessary.

In an embodiment, a transducer cartridge as described herein includes athermally conductive plate or a heat transfer plate incorporated intothe lower compartment. The lower compartment (cartridge) may have aplate in direct contact with the fluid sealed within the cartridge. Inone aspect, the heat transfer plate coincides with the surface used toat least partially engage with the upper compartment. This allows heatabsorbed by the heat transfer plate to at least partially radiate theheat into the upper compartment.

In an embodiment, the upper compartment has a heat exchanger in the formof a heat absorption component adapted to work with the heat transferplate in the lower compartment. The heat absorption component of theupper compartment and the heat transfer plate of the lower compartmentdo not need to be the same physical size or foot print, so long as theyoperate to transfer heat as necessary out of the cartridge. The heatabsorption component takes heat away from the cartridge through the heattransfer plate. Once heat is transferred from the heat transfer plate tothe heat absorption device, the temperature in the cartridge is reduced.This heat transfer can be done continuously to set the temperature ofthe fluid within the cartridge, or periodically based on need. Forinstance, the heat transfer function may be set to automatically operateif a temperature sensor in the cartridge detects the fluid temperatureexceeds a preset threshold range of about one (1) to thirty seven (37)degrees centigrade. In an embodiment, the threshold range may benarrowed to about five (5) to eighteen (18) degrees centigrade. Inanother embodiment, the fluid temperature may be adjusted to assist withnumbing the skin of a patient by chilling the skin. The fluidtemperature may be lowered to about one (1) to seven (7) degreescentigrade.

In an embodiment, the heat absorption component is a thermoelectricdevice, like a layer of thermal electric chips (TEC). The layer ofthermal electric chips may be a single large chip, or a group of chipslaid out next to each other to form a grid of chips. TECs produce athermal gradient between the two faces of the chip when an electriccurrent is introduced to the TEC. The cool side of the chip faces theheat transfer plate of the cartridge, while the hot side of the chip(s)face away from the lower compartment.

Heat is drawn away from the thermal electric device layer by using aheat sink attached to the thermal electric device layer. The heat sinkmay be a fluid filled bath having a chilled fluid circulated through it(e.g. from the fluid circulation system described in one aspect herein).The heat sink may also be a highly conductive thermal material (likecopper or aluminum) formed into an air cooled device. If air cooled, asmall fan may be included in the upper compartment for continuallymoving air across the heat sink. The upper compartment would furtherhave both air inlet and exhaust vents for drawing in cool air andventing warm air.

In an embodiment, the heat absorption component is itself one of theabove mentioned heat sinks (liquid filled bath or air cooled heat sink).In this embodiment the heat transfer plate is still formed into thecartridge, however instead of using a thermal electric device layer toremove heat from the cartridge, a heat sink is used. A fluid heatabsorption layer may used and supplied with a chilled fluid from thecart. Activation of the heat absorption component may be preprogrammedfor a variety of situations, such as when the fluid temperature of thecartridge exceeds a certain value or to maintain a certain temperaturein the cartridge.

In an embodiment, the heat transfer plate of the cartridge may bereplaced with a heat exchanger within the sealed fluid enclosure of thecartridge. Inside the cartridge, a heat conducting pipe is positionedwithin the cartridge so as to maximize the surface area of the heatexchanger (and thus maximize the thermal transfer area) while avoidingthat volume of space within the cartridge needed for the transducerassembly to move freely. The heat exchanging pipe may be made of copper,aluminum, stainless steel or other materials (including plastic) so longas the tubing is sufficiently thin walled (thermally conductive) toallow heat transfer from the cartridge environment into the fluid in theheat exchanging pipes. The heat exchanger should also avoid interferingin the broadcast of ultrasound energy from the transducer through thetransmission window. The heat exchanger may be a coil arranged in aserial configuration (as in a continuous winding of the coil), aparallel configuration (as in two or more pipes arranged in parallelalignment and fed from a single input, and drained from a singleoutput), or a winding configuration (a mix of serpentine and/or straightpaths) and any combination of these configurations are equally usable asa coil heat exchanger. In another embodiment, the heat exchanger may bea sealed plate with either serial or parallel water paths integratedinto the sealed plate so as to function similar to a coil or pipearrangement.

In one aspect the heat exchanger is liquid filled, however it is notnecessarily the same liquid used in the fluid tight sealed enclosure ofthe cartridge. This allows the liquid in the heat exchanger to becirculated with the liquid from the fluid circulation system withoutcompromising the structural and isolation integrity of the degassedliquid volume sealed within the cartridge. Once again the fluid in theheat exchanger is circulated with chilled fluid from the fluidcirculation system and is activated on demand based on eitherpreprogrammed parameters or user command. Note the fluid circulationsystem in any of the embodiments described herein may be set to “Alwayson” so that liquid circulation is always occurring. Chilling of theliquid circulating in the circuit may similarly be set for “always on.”Because the liquid circulation fluid is separated from the liquid sealedwithin the cartridge, degassing is not required of the fluid in thecart/fluid circulation system. In an embodiment, the cartridge may befilled with a non-liquid fluid, such as a gas prior to actual use, andfilled with a static coupling liquid just prior to use.

Various coupling and cooling fluids are used in or with the variousembodiments and aspects described herein. The coupling and coolingfluids used may be similar in composition and treatment, or they may behighly variable. In one aspect, the coupling fluid used in the cartridgemay be degassed water. Water degassed to less than 12 ppm of dissolvedoxygen may be used as a coupling fluid inside the cartridge. In anotheraspect, the level of oxygen in the degassed water is about 8 ppm and inanother aspect the level of degasses oxygen may be about 5 ppm or less.In another aspect, the coupling fluid inside the cartridge may containadditives to extend the life of the cartridge (such as a biocide toincrease the shelf life) or other additives that may improve the deviceperformance or improve shelf life. In an aspect of the invention, theuse of a metallization layer or sputter metal material promotes theshelf life of the cartridge relating to extending the duration in whichdegassed water may maintain the low level of dissolved gasses within thecartridge. The level or amount of metallization needed may be derivedusing the formula wherein a thickness of the metallization layer is lessthan X, where X=[((α−0.09)*1000)/0.03]+500, with X being themetallization layer thickness in Angstroms, and α being a maximumacceptable acoustic attenuation in dB in a transmission window.

In another aspect, the coupling fluid inside the cartridge may containvarious concentrations of salts. A salt solution inside the therapy headshould have sufficient ultrasound transparency to allow the system tobroadcast the desired amount of energy. . A salt solution helps toprevent gas absorption in the solution as well, and may reduce thepossibility of producing cavitation or micro streaming events within thecartridge. The salt concentration will depend on the kind of salt used,and the desired fluid characteristic the salt concentration can provide.For the purposes of maintaining a degassed coupling solution in thecartridge, a salt solution and/or a metallization layer can be used.

In one non-limiting example, a calcium chloride (CaCl) salt was added towater for use as a coupling solution inside the cartridge. Increasingthe CaCl concentration range to about ten (10) percent by weight toabout twenty one (21) percent by weight to help reduce the incidence offreezing (by lowering the freezing point of the water) and reducing thelikelihood of cavitation (by preventing gas bubble formation duringoperation of the ultrasound transducer) while maintaining a desiredtransparency of ultrasound energy through the salt solution. The levelof CaCl may be increased or decreased as desired, and other saltsprobably may be used to produce a similar effect.

The cooling fluid used inside the ultrasound system may be water in anembodiment. The cooling fluid generally has a high thermal absorptioncapability, such as water, or a water mixture with other chemicals.Chemicals that may be used include a biocide (to prevent bacterialgrowth in the fluid circulation system), a chemical additive (for systemdetection purposes) or other ingredients that may increase the fluidsystem performance or longevity.

Outside the therapy head and cartridge, another coupling solution can beused to couple ultrasound energy between the medical system and thepatient. In an embodiment, this coupling solution may be a watersolution that is ninety-nine percent (99%) pure water, with less thanone percent (1%) of impurities (excluding dissolved or suspended gases).In another embodiment, the patient side coupling solution may be a lightmineral oil or other fluid having similar viscosity characteristics ofwater. An aspect of the system of the invention is to use a couplingsolution outside the body that is drawn from the same reservoir as thecooling liquid of the fluid circulation system. In this aspect, theliquid is circulated from the base unit to the therapy head body, andthen dispensed from the therapy head body onto a patient's skin.

In an aspect of the system of the invention, fluid from the fluidcirculation system flows directly into the sealed fluid enclosure of thecartridge. In this embodiment, the cartridge is not sealed with adegassed fluid. Instead once the cartridge is connected to the uppercompartment, the cartridge is flooded using fluid from the fluidcirculation system. In this embodiment, a degas unit may be used toreduce the dissolved gas level in the fluid prior to treatment. In oneaspect the fluid may be degassed down to about five (5) to ten (10) ppmor lower dissolved oxygen (oxygen being used as a common meter for allother dissolved gasses based on proportion of gas dissolution). Achiller may also be used to cool the water in this embodiment. No dripfluid connectors may be used between the cartridge and the treatmenthead and/or circulation system to reduce liquid leakage during cartridgereplacements.

In an embodiment, the treatment head may be designed using the smallersize and components of the system described above, but retain aremovable transducer cartridge that leaves the transducer assemblyremovably connected to the upper compartment. In this embodiment, thesystem replicates the process of draining the fluid from the treatmenthead by evacuating the fluid chamber of the treatment head. The userthen removes the transducer cartridge and replaces the transducer. Thesystem then refills the fluid chamber inside the treatment head. Thefluid in this embodiment also requires degassing. A degas device for usewith these embodiments is provided herein. The degas device is connectedto the fluidics system in the base unit, and utilizes a single pump toboth move the fluid through the system, as well as force the fluidthrough a chamber for removing dissolved gasses. To reduce liquidspillage during cartridge replacement, “no drip” fluid connectors may beused, which shut off the liquid supply on the inlet and outlet liquidlines when the cartridge is replaced.

The degas unit according to this embodiment is a system for separatinggas from a gas-containing liquid. The degassing system includes a flowrestriction component in fluid communication with a supply of thegas-containing liquid, a pump in fluid communication with the flowrestriction component, a separation chamber in fluid communication withthe flow restriction component through the pump, one or more gasoutlet(s) in fluid communication with the separation chamber, and adegassed fluid outlet in fluid communication with the separationchamber. The pump is configured to draw a flow of the gas-containingliquid through the flow restriction to create a solution of liquid withgas bubbles. The separation chamber is configured for gravity inducedseparation between the gas bubbles and the liquid. In this embodiment,gases are drawn out of solution by pulling the liquid through a smallorifice. As the liquid escapes the orifice it experiences a region ofnegative pressure causing bubbles to form. The bubbles and liquid flowthrough a pump and into a separation chamber. The separation chamber isunder positive pressure to slow down the escape of the gas bubble andliquid solution through the gas outlet(s). The separation chamber isplaced within a ventilation chamber that is also under positivepressure. As the gas and liquid solution exit the separation chamber andenter the ventilation chamber, the gas bubbles float up, and thedegassed liquid is pushed down through a liquid outlet duct.

In another embodiment, a system for separating gas from a gas-containingliquid is provided. The degassing system may include a pair of degasfilters arranged serially. A liquid may be drawn through a flowrestriction component to produce gas bubbles. The liquid is then pushedthrough a first degas filter, where gas bubbles are vented out. Theliquid continues to a second gas filter that has a vent line connectingto the liquid line just prior to the intake section of the pump. Thevent line provides a vacuum on the second gas filter so that dissolvedgasses may be drawn out of solution and vented out of the liquid. Theliquid then can be used in a fluid circuit calling for degassed, orreduced dissolved gas, liquid. The liquid circulates back into the degassystem near the pump intake. The degas system may include a reservoir,in which case the liquid circuit return may flow into the reservoir.

In another embodiment, medical ultrasound systems are provided. Themedical ultrasound systems include an ultrasound therapy head and adegassing system. The ultrasound therapy head includes an ultrasoundtransducer that is at least partially surrounded by a coupling fluid.The degassing system is typically located in the base unit andincorporated into the liquid circulation system. A liquid circuit pumpsliquid from a reservoir, through a degas device and to the therapy headso as to supply degassed coupling fluid to the therapy head. In oneaspect, the degassing system includes a flow restriction in fluidcommunication with a supply of coupling fluid, a pump in fluidcommunication with the flow restriction, a separation chamber in fluidcommunication with the flow restriction through the pump, a gas outletin fluid communication with the separation chamber, and a degassed fluidoutlet in fluid communication with the separation chamber. The pump canbe configured to draw a flow of the coupling fluid through therestriction to create a solution of coupling fluid with gas bubbles. Theseparation chamber also or alternatively can be configured for gravityinduced separation between the gas bubbles and the coupling fluid.

In an embodiment, a fluid coupling device adapted for use with anultrasound treatment head is provided. A treatment head like anydescribed herein or being substantially equivalent to such acomponent/device, may be equipped with a coupling fluid dispenser. Thedispenser draws from the fluidics system of the ultrasound system forfluid. The liquid used as a coolant in the treatment head, and as a heatsink for the ultrasound transducer, may also be used to couple thetreatment head to a patient body by dispersing it on to the patient.This is achieved by having a separate fluid conduit from the treatmenthead, to a volume of space outside the treatment head. The conduit maybe under additional pressure from the fluidics system normal pressure,or it may be the same or less pressure than the fluidics system. Thefluid drawn from the fluidics system is dispensed on a patient bodyprior to placing the treatment head on the skin surface. The fluid maybe sprayed, sprinkled, dropped, or in any fashion dispersed over thepatient skin surface prior to treatment. The fluid dispersion may bethrough an aerosolizer, mister or other dispensing mechanism. In oneaspect the dispensing of the fluid is controlled by the user so thefluid may be accurately delivered and evenly distributed on the skinsurface, and such delivery and distribution is on demand through anactuation device such as a button, trigger, or othermechanical/electromechanical method. The system may also control theduration of the spray to optimize the application of the fluid forproper coupling of the treatment head to the patient, and/or to avoidinadvertent draining of the tank.

Several embodiments of using the system on a patient for body sculptingare now described. In one embodiment a template for creating treatmentlines on a patient body is provided. The template can be made of, e.g. adisposable, light weight material that is safe for clinical use. Any ofa variety of plastic materials, bio-polymers, or other suitable materialsuch as approved and/or safe for clinical use may be used. The templatehas at least one straight line drawn on it, and typically has multipleslot shaped apertures in the template that run perpendicular to thedrawn straight line. In use the template is placed on a patient body,such as the abdomen or flank region, and a user takes a marking pen orsimilar device and creates lines on the patient body through the slotshaped apertures. The user then rotates the template 90 degrees (or anapproximation thereto) so the template straight line is laid over one ofthe previously drawn lines on the patient skin. The user then drawsadditional lines through the slot shaped apertures so as to create asquare grid approximately the same size as the slot shaped apertures ofthe template. The user repeats this process until the entire surfacearea desired to be treated is covered with grid lines.

The treatment head has alignment features on the sides of the treatmenthead. In one aspect the alignment features are on all four sides of thetreatment head. In another aspect the alignment features are on adjacentsides or opposite sides. The alignment features are used to “eye ball”the position of the transducer over the drawn grid lines by placing thealignment features over the drawn lines. If only two alignment featuresare used, the features are either on opposing or adjacent side walls ofthe treatment head, and the treatment head can be aligned by using asingle straight line, or the “right angle” created by two intersectinglines. This allows the placement of the treatment head on theintersection of the drawn grid lines and using the midlines as thereference marker(s) for treatment.

If a complete grid is drawn on the patient, then the spacing of thelines of the grid do not have to line up with the size of the treatmenthead face (as long as they are smaller than the treatable area of thetreatment head if spaces between sites are not desired). In effect thealignment of the therapy head is placed on the center lines of thehorizontal and vertical lines of the grid rather than centered on thearea encompassed by the lines. This allows for a given treatment headwith its physical treatment head area to not have to match the treatmentarea the user may want. In other words, a given treatment head area(size) can be used with multiple grid size templates based on the areaand shape of the desired treatment region.

If we allow variable site areas and supply various templates to mark thelines, a verification feature is need to minimize the chance a usermight make an error by marking one size grid on the patient and thensetting up the system to treat a different size site. To minimize thischance a feature the system can read can be embedded into the template.In such an embodiment, after the user marks the patient, the userpresents the template to the system to have it read the marked site areato set up the machine to match the patient markings This feature couldbe implemented with, e.g., an embedded barcode on the marking templateor with radio frequency identification (RFID) type tags embedded intothe template. In either case the user would “scan” the template into thesystem to allow entering the treatment screen to set up the system forthe correct site area. A scan of the template refers to readinginformation from the template, such as a bard code, radio frequencyidentification (RFID), electronic code or other information containingdevice on the template.

In an embodiment, the system has a “scan” capability able to record theposition of the grid lines on the patient body. The system ability toscan with reference to reading grid lines or the patient body may betaking a picture of the treatment area and using image recognition tofind the lines on the patient body. Alternatively or in addition, thesystem may record the position of boundary lines created in the patientbody that provide demarcation of safe treatment areas and non-treatmentareas. Creation of the boundary lines is typically done prior to placingthe therapy head on the patient body. Once the user has selected aparticular treatment site (for instance near the edge of the treatmentsurface), the user may subdivide the area of the treatment surface ofthe treatment site under the therapy head into one or more treatmentareas and one or more non-treatment areas. The system would then eithercreate the treatment area control commands or use pre-defined tablesgenerated off line to send to the control hardware to treat the userdefined areas while avoiding the areas designated as a non-treatmentarea. In this embodiment, the display acts as a drawing tablet allowingthe user to display either the actual grid line on the patient surface,or a representation of the gridline (in which case no system scanning ofgrid lines on a patient body capability is needed). The user can createdividing boundaries, either on the patient's skin or on the visualdisplay that designated one or more sections as either safe fortreatment or conversely, as non treatment regions. The image displayedcan clearly indicate which of the sections, demarcated by the drawnlines, are to be used for treatment and which are not to be used fortreatment. The boundary indications are not limited in shape, size ornumber. Indication of treatment safe or non treatment regions either onthe display or on the patient may be made by using different color orpattern markers, designating the regions as treatment or non-treatmenton the display. This application is helpful to treat around theumbilicus (belly button) and areas where the area of treatment may besmaller than the area of a complete grid square (such as under thecheek, arms or other spots of relatively low subcutaneous adipose tissueaccumulation). The system has an enhanced software capability to convertthe user defined safe and no treatment zones into operationalinstructions for controlling either the movement of the transducerassembly so the transducer does not move over the non-treatment areas,or a transducer control feature that allows the transducer to stopbroadcasting ultrasound energy as it sweeps over the non-treatmentareas. The display and subdividing of the treatment surface could alsobe applied to more than one site at a time, up to the entire treatmentsurface.

Generally, treatment of the body to produce the desired body contouringresults, utilizes sufficient energy to produce a therapeutic effect. AnEnergy Flux value between 35-460 Joules per square centimeter at theskin surface (J/cm²) is generally required. The energy flux (EF) valuemay be derived using the formula:[(p)×(l/v)×(dc)×(nl)]/(sa)

wherein

p=power,

l=line length,

v=velocity,

dc=duty cycle,

nl=number of lines

and

sa=scanned area.

The formulation provided provides for a calculation when the transduceris moving continuously while applying ultrasound energy. Alternativelyfor a treatment program where the transducer is not moving betweentherapy applications, the EF can be calculated using the followingmodified EF equation.EF=[(p)×(t)×(dc)×(ns)]/(sa)

wherein

p=power,

t=on-time per lesion,

dc=duty cycle,

ns=number of lesions,

and

sa=scanned area.

Further details are provided on in co-pending U.S. patent applicationSer. No. 11/414,080 entitled Apparatus and Methods for the Destructionof Adipose Tissue, herein incorporated by reference.

In the description of the drawings below, multiple exemplary embodimentsof the invention are described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practiceswithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed. To preserve ease of reading, parts are labeled with the samenumber where they serve the same function from embodiment to embodiment.For instance, no less than five different versions of a cartridge (partnumber 600) are herein described. Each transducer cartridge isidentified as part 600 even though numerous embodiments are described,with many more equivalents not described, but will be suggested orapparent to the reader skilled in the art. The use of a common numeralfor the many parts detailed herein is not to be taken to indicate thatthe part is exactly the same physical part from embodiment toembodiment, but rather has the same function from described embodimentto embodiment. Items with the same part numbered are not necessarilystructural equivalents, since various embodiments may be highlydivergent physically from one another.

The nature of the systems and apparatus described herein are those ofelectronic devices. There are electrical signals being sent from variousparts or sub systems to other parts and sub systems, as well aselectrical power sent to those same parts (components) and sub systems.The transfer of electrons between any component with any other componentis referred to herein as electrical communication. Electricalcommunication may be signals or power, used to direct, sense, control orsimply turn on/off a component. The passage of electrons through anyintended conduit for electrons, regardless of voltage, amperage orwattage is also electrical communication. Electrical communicationincludes signals sent and received by wireless systems or methods ifincorporated to any part of the disclosure herein.

Furthermore, the nature of systems of the invention as described in themany embodiments involves the use of various liquids. These may becooling liquids, coupling liquids, storage liquids or liquids used forany other purpose. Supply or transportation of any of these liquids fromone of the various components to another component designed or intendedto receive, use, transfer or touch any of these liquids is referred toherein as fluid communication.

A system of the prior art is shown in FIG. 1. The system P10 has a cartbase P12 with a mechanical arm P14 supporting a therapy head P20 with aremovable cap P22. The system also has a display screen P16. The entiresystem P10 weighs in excess of 300 pounds (136+ kg), and stands about1.3 meters high, about 1.1 meters deep and about 62 cm wide.Individually the therapy head P20 weighs about 3.5-4.0 kg, and the armP14 weighs about 32 kg. All weights excluding any fluid or liquid thatis normally required for the system to operate. The size and weight ofthe system makes it difficult to transport, and it can be cumbersome andunwieldy.

An embodiment of the present invention is now shown in FIGS. 2-4. Amedical ultrasound system 100 is shown having a display 102, a base/baseunit or main body 130 with a front face 108 with one or more apertures118 therein. The apertures 118 are receptacles for receiving a therapyhead 500. The front face 108 may have one or more apertures 118 for acorresponding number of therapy heads 500. The main body 130 includesthe front face 108 and a back face 132 (See FIG. 5). The main body 130is attached to a base 106 which is fitted to receive casters 104. Thebase may be integrated into the main body, or separated as shown. Thesystem 100 is shown having a main compartment 112 behind the face plate108. The design of the system 100 can be such that the front face 108 iskept clear for aesthetic appearance. The location of the maincompartment 112 containing system electronics is not crucial to thelayout of the main body 130. The system 100 may include a handle or pairof handles 110 in order for a user to grasp the system and maneuver iton its castors 104. The system 100 can include one or more input jacks120 for a foot pedal switch (not shown). A cable 116 connects the system100 with a treatment head 500. The treatment head(s) 500 may rest in thetreatment head apertures 118 where the cables 116 are plugged in,however it is not a limitation of the present invention that a treatmenthead must be inserted into the same receptacle as the cable whichconnects it to the main body 130. Indeed treatment heads 500 may bepositioned in any available receptacle 118 regardless of whether theyare plugged in to a cable or not.

Alternatively the treatment heads 500 of the medical ultrasound system100 need not be stored in the receptacles 118 of the system 100 when notin use. The treatment heads 500 may be disconnected if desired andstored anywhere at the user's discretion. A single treatment headversion is shown in FIG. 3. Where multiple treatment heads 500A, 500Bare shown, there can be a corresponding number of receiving apertures118A, 118B and cable plugs 122A, 122B (See FIG. 4). In an aspect of thetreatment head, the treatment head may be about 80 mm on a side and havea generally rounded rectangular or circular foot print. The treatmenthead may be about 150-180 mm in height and weigh about 200 to 500 grams.In another aspect the treatment head may weigh between 300 and 400grams, and in another aspect the treatment head may weigh about 330-360grams.

A profile view of the main body 130 is shown in FIG. 5. The display 102is supported by a neck 126 which can be folded down. The display 102 isalso mounted to the neck via a moveable joint, the joint may allow thescreen to tilt, rotate or swivel. The apertures 118 for the treatmentheads have a catch or back plane 124 to prevent the treatment heads fromsliding completely through the apertures. In one aspect the receptaclesare formed to provide a snug fit for the treatment heads so thetreatment heads are securely positioned on the main body when storedthere. The system has a back plate 132, and main compartment 112 has acover 134 that is removable. The base unit may weigh about 25-40kilograms (kg), and in various aspects may weigh 28-35 kg (withoutliquid). The base unit may stand about 1.4 meters (m) in height, and beabout 50-75 centimeters (cm) in width and depth. These dimensions do notcount any cabling or peripherals that may be connected to the base unit.

FIG. 6 provides a transparent view of the major system components of themain compartment 112 of an embodiment of the system. The bulk of thesystem electronics 200 are mounted within the main compartment 112. Theinternal electronics are supported by a set of structural supports 214,216 that anchor the electronics in place while providing the orientationfor air flow through the compartment. An air circulation system 202 isprovided using one or more cooling fan(s). Air is drawn in by the fansand flows past a fluid chiller unit. Air flows into a cavity near thebase of the unit, and then is channeled into one of two paths. One pathgoes through the main circuit board cage 212, along airflow path 254.The other paths flows through the power supply 204, along flow path 254to help cool the power supply 204. The power supply may be positionedbelow the base 106, with the flow path 254 through the power supplyadjusted to flow through an aperture (not shown) in the base 106. AnEthernet port 206 is provided to allow the system 100 to connect to anLAN or internet portal. The card cage 212 may have a back plane 210 thatprovides both structure to the card cage, and bus or plugs for systemcomponents. In one aspect the back plane is eliminated (excluded) byusing a pair of printed circuit boards adapted to interface directlywith each other. A fluid circulation system 208 is stacked on thesupport strut 216. The fluid circulation system has at least one pumpand filter set 220 for moving the fluid through the system, andfiltering the fluid to preserve fluid quality. The fluid for the system(not shown) can be a liquid having low viscosity and high thermalcapacity. Liquid water can be used as a fluid for the circulationsystem. More particularly the fluid may be degassed liquid water,chilled liquid water. Other suitable fluids can be used. Alternatively,part or all of the air intake may be used to cool a water storage tank,or water cooling system.

A profile view of the main compartment system electronics of anembodiment of the system is shown in FIG. 7. The airflow path of the twoair flow ducts are shown by the dotted arrows. The first air flow path252 cools the card cage. The first duct draws air through the systemcover, and drives the air into a hollow space below the card cage 212.The hollow space is defined by the support strut 214 and the componentsstacked on the strut 216. The card cage 212 is designed to orient cardsin a generally vertical alignment with air flow space between the cards.Air is pushed into the hollow space, and drawn up into the card cage bythermal convection. Hot air from the card cage rises and flows outthrough a vent in the compartment cover. The second air flow path 254helps cool the power supply 204. Air is drawn into the system through aninput pathway 250 in the air circulation system 202. Once the aircirculation system is active, the interior space of the main compartmentbecomes slightly pressurized. The power supply 204 has a fan for drawingin air from the system, while the card cage relies on forced convectionto draw cool air from the bottom, while warm air rises out the top flowpath 252. Alternatively the card cage may have a fan for drawing coolair into the card cage, or for venting warm air out through the exhaustvent. If the base has a water chiller, then the air flow can pass over aheat exchanger for the water chiller in addition to the other componentsdescribed above. The air can flow over the various components in anysuitable order.

A perspective view of the main compartment 112 with cover of anembodiment of the system is provided in FIG. 8. The back plane of thecard cage 212 is shown extending from the top of the compartment. Thefront face 108 and back face 132 are not shown in this view.

One component of the fluid circulation system 208 may include a degasdevice used to extract dissolved gasses from the fluid in the fluidcirculation system. The inclusion and use of a degas device maygenerally be avoided.

FIG. 9 shows a degassing system 340 in accordance with an embodiment.The degassing system 340 includes a retaining wall 342 connected with abase 344 that is below retaining wall 342. The combination of the sidewall 342 and the base assembly 344 form a liquid reservoir 346 that isliquid tight. A separation device 348 is disposed within the reservoir346 and connected with the base 344. The reservoir 346 holds agas-containing liquid 350, such as those liquids described herein, thatare to be degassed. The base 344 includes a supply duct or conduit 352that can be used to add or remove the gas-containing liquid 350 to orfrom the reservoir 346. The base 344 may also include a separate drainline. The base includes a degas fluid carrying duct or conduit 354 fordrawing degassed fluid from the ventilation chamber 366. The base 344includes a liquid flow restriction component or device 356, a firstfluid channel 358, a pump 360, and a second fluid channel 362. The flowrestriction component 356 is located at the bottom of the fluidreservoir 346 and is in fluid communication with the reservoir 346. Thefirst fluid channel 358 is positioned between the flow restrictiondevice 356 and the pump 360 and places the flow restriction device 356in fluid communication with the pump 360. The flow restriction devicemay be a nozzle, valve or other device that restricts the flow ratesufficiently for liquid flow to be sucked through the flow restrictiondevice by a negative pressure created by the pump 360. By drawing waterthrough the flow restriction device 356, dissolved gasses are broughtout of solution by creating a negative pressure (about 1-2.5 PSIabsolute) inside the first fluid channel 358. The fluid with air bubblesthen passes through the pump 360, the second fluid channel 362, and intothe separation chamber 382. Gas bubbles pass from the fluid chamber 382into the chamber 366 and float upward, while degassed fluid is availableto be drawn out through conduit 354. In one aspect the separationchamber is under positive pressure (approximately +10-20 PSI gaugepressure) forcing gas bubbles through the exit port 372. A pressuretransducer (not shown) can be located to monitor the pressure within thefirst fluid channel 358. The second fluid channel 362 is positionedbetween the pump 360 and the separation device 348 and places the pump360 in fluid communication with the separation device 348.

The separation device 348 includes an outer housing 364 that defines aseparation or degas chamber 366. Outer housing 364 includes at least oneside wall 368 connected with the base assembly 344 and at least onesloped upper wall 370 connected with the side wall 368. The sloped upperwall 370 is connected with an exit port 372 that is in fluidcommunication with the separation chamber 366. The exit port 372 isconnected with, and is in fluid communication with, a gas bubble exhaust374. The gas bubble exhaust 374 has an upper portion 376 that isdisposed above an exit port 378. Exit port 378 places the exit port 372in fluid communication with the fluid reservoir 346.

Disposed within separation chamber 366 is a distribution manifold 380that is connected with the base assembly 344. The distribution manifold380 defines an inner chamber within the degas chamber 366. Thecombination of the distribution manifold 380 and the base assembly 344defines the inner chamber 382 that is disposed above, and is in fluidcommunication with, the second fluid channel 362. The distributionmanifold 380 includes one or more orifices 384 that place the innerchamber 382 in fluid communication with the separation chamber 366.Orifices 384 are located in the upper portion of the distributionmanifold 380.

FIG. 10 illustrates the operation of the degassing system 340 of FIG. 9.Gas-containing liquid 350 is drawn from the fluid reservoir 346 throughflow restriction device 356 into the first fluid channel 358 by theoperation of pump 360 such that gas dissolved within the liquid comesout of solution and forms gas bubbles. The flow of fluid through thepump generates a strong negative pressure which reduces the pressurelevel within the first fluid channel 358 relative to the fluid reservoir346. The flow restriction component can be about a 0.039 inch diameterorifice (such as a drilled hole, nozzle or similar component). Thepressure drop helps to bring dissolved gas out of solution therebyforming bubbles in the fluid (361 in FIG. 34). In some embodiments, theflow restriction is chosen and the flow rate is selected and/orcontrolled to reduce the pressure in the first fluid channel 358 tobetween about 1.0 to about 2.5 PSI absolute. When the gas-containingliquid is water, further reduction in the pressure (e.g., below 0.9 to0.95 PSI absolute) in the first fluid channel 358 may cause cavitations,which can damage system components such as the pump 360. A pressurelevel of above about 1.0 PSI absolute has been found to be a goodcomprise between achieving maximum degassing while maintaining apressure margin so as to generally avoid cavitation. A balance ofnegative pressure in the first fluid channel 358 and pump integrity canreduce or prevent damage to the system and/or pump. The pump flow rateis not fixed, but depends on the relation of the size of the flowrestriction device 356 and the desired level of negative pressure. Aweaker pump may be used with a smaller flow restriction, while astronger pump is typically desirable with a larger flow restrictiondiameter device. Balancing pump capability and restriction size can alsobe matched with the physical integrity of the pump to withstandcavitation damage. The flow restriction typically generates turbulentflow, which may further encourage the formation of gas bubbles. Apressure transducer can be integrated into the first fluid channel 358and the output from the transducer used to regulate the speed of thepump 360 so as to maintain the desired pressure level within the firstfluid channel 358.

The liquid and gas bubbles are then transferred to the separation device348. The pump 360 transfers the liquid and gas bubbles from the firstfluid channel 358 to the inner chamber 382 of the distribution manifold380. From the inner chamber 382, the liquid and gas bubbles aretransferred to the middle portion 386 of the separation chamber 366through the orifices 384.

The separation chamber 366 is configured for gravity induced separationbetween the gas bubbles and the liquid. The distribution manifold 380introduces the liquid and gas bubbles in such as way as to minimize theamount of circulation and/or mixing of the previously separated bubblesand liquid within the separation chamber 366. The orifices 384 aresmall, thereby inducing slow flow, which reduces the amount ofcirculation and associated mixing that occurs within the separationchamber 366. The orifices 384 are located in a middle portion 386 of theseparation chamber 366, which keeps the bubbles from entering a lowerportion 388 of the separation chamber 366. By reducing the amount ofcirculation and/or mixing, the bubbles, due to their reduced density ascompared to the surrounding liquid, can rise towards the top of theseparation chamber without being carried lower by downward flow. Thedistribution manifold 380 introduces the liquid and gas bubbles in themiddle portion 386 of the separation chamber 366, thereby isolating thedegassed liquid disposed in the lower portion 388 of the separationchamber 366 by not causing circulation within the lower portion 388.This isolation helps to keep any gas bubbles from being carried into thelower portion 388 so that the degassed liquid extracted from theseparation chamber by a degassed fluid outlet 390 can be substantiallyfree from any gas bubbles. The degassed fluid outlet 390 is in fluidcommunication with the degassed fluid conduit 354, which is used totransfer the degassed fluid from the system.

The rising gas bubbles are removed from the separation chamber 366through the exit port 372 located at the top of the upper portion 392 ofthe separation chamber 366. The separation chamber 366 can be configuredto direct the gas bubbles to the exit port 372, such as by usingconically shaped upper sloped walls 370 in the upper portion 392 asshown. The gas bubbles are forced to the gas bubble exhaust 374, whichserves to prevent the surrounding gas-containing liquid 350 fromentering the separation chamber 366 through the exit port 372 while thesystem is operating. The gas bubble exhaust 374 includes an upperportion 376 and an isolator exit port 378. The gas separated from thegas-containing liquid is transferred to the gas bubble exhaust 374 fromwhich it exits at the exhaust exit port 378. The gas bubble exhaust 374can be any number of isolating devices. The bubble exhaust 378 may bedirected downward into the bottom of the reservoir to assist in drainingthe reservoir when the pump is operated in reverse.

The configuration of the degassing system 340 provides for simplifiedflow rate control. During operation, the pump 360 can be run at aconstant speed or the speed of the pump 360 can be controlled by aclosed control loop so as to maintain a desired pressure within thefirst fluid channel 358. With a flow restriction component 356 of a setsize, the resulting pump operating speed will typically not vary to anylarge extent, which produces a substantially constant flow of liquid andgas bubbles to the separation device. The substantially constant flow ofliquid and gas bubbles to the separation device provides a supply ofdegassed liquid to replace degassed liquid extracted from the separationchamber. As long as the degassed liquid is extracted at an equal orlower rate than it is generated, any excess degassed liquid flows out ofthe separation chamber via the exit port 372 and the isolator 374 alongwith the removed gas. For example, degassed liquid can be extracted fromthe separation chamber at a rate of 300 ml/min while a 500 ml/min flowof liquid and gas bubbles can be supplied to the separation device 348.The extracted degassed liquid (e.g., water) can be circulated for use asa coupling agent in an ultrasound therapy head, such as for use in thelower compartment 320 of the therapy head 318 as shown in FIG. 2.

An inflatable bladder or other pressure regulating device (not shown)can be used to maintain and/or regulate the pressure of the fluidreservoir 346.

In an embodiment, the degas system may use two degas filters in series(FIG. 10B). The degas system utilizes a single pump 1002 to move thefluid through the entire fluidics system, and produce the pressureenvironments necessary to degas the liquid within the system. The liquidmay be contained in a reservoir 1004 and can be drawn through a pump1002. The liquid then is pushed into a first degas filter 1010 wherebubbles are vented to the atmosphere (alternatively the bubbles may bevented into the reservoir, not shown). The liquid then flows into asecond degas filter that has a vent line going into the input line thatis drawn into the pump. The pump creates a negative pressure (vacuum) inthe degas filter 1012 and helps to removed dissolved gases from theliquid. The liquid then goes through a fluid circuit 1006, such as to atherapy head for an ultrasound transducer, or the like. The liquidreturns from the fluid circuit 1006 and either goes to a reservoir 1004,or back toward the pump 1002. As the fluid circuit operates, air bubblefrom the return line, reservoir or vent line 1014 move through the pumpand go to the first degas filter 1010, where the bubble percolate andvent out of the degas liquid line. Degassing of the liquid occurs in thesecond filter 1012 which is under vacuum through the second vent line1016.

FIG. 11 is a schematic diagram illustrating a degassing system 3100 inaccordance with another embodiment. Similar to the degassing system 340discussed above, the degassing system 3100 includes a flow restriction3102. The degassing system 3100 further includes a first fluid channel3104, a pump 3106, a first degas filter 3108, and an optional seconddegas filter 3110. The flow restriction 3102 is in fluid communicationwith a source of gas-containing liquid 3112. The first fluid channel3104 places the flow restriction in fluid communication with the pump3106. An output of the pump 3106 is in fluid communication with thefirst degas filter 3108. The first degas filter 3108 includes a gaspermeable membrane 3114 that allows the passage of gas whilesubstantially preventing the passage of liquid. A vacuum is required onthe gas side of the gas permeable membrane 3114 thereby creating apressure differential across the gas permeable membrane 3114. The gasside may vent to the atmosphere via a vent 3116 that may include apressure valve. The optional second degas filter 3110 includes a gaspermeable membrane 3120 that allows the passage of gas whilesubstantially preventing the passage of liquid. The gas side of the gaspermeable membrane 3120 is vented to the first fluid channel 3104 viaconduit 3122.

In operation, a gas-containing liquid is drawn through the flowrestriction 3102 into the first fluid channel 3104 by the action of pump3106, which causes the gas dissolved within the liquid to come out ofsolution as discussed above with reference to degassing system 340. Thegeneration of the gas bubbles in the degassing system 3100 can besubstantially the same as in the degassing system 340 discussed above.

The liquid and gas bubbles are then transferred to the first degasfilter 3108. The pressure of the combination of the liquid and gasbubbles within the first degas filter 3108 is greater than atmosphericpressure due to the action of pump 3106. Because the gas side of the gaspermeable membrane 3114 is under a negative pressure relative to thecombination of the liquid and gas side, causing gas to pass through thefilter to the gas side. Gas removed from the fluid in this way may bevented out of the system through a one way valve. The pressuredifferential serves to force gas from the liquid and gas bubbles side ofthe permeable membrane to the gas side of the permeable membrane, whereit can be vented to the atmosphere or collected. Degassed liquid 3118exits the first degas filter 3108.

The degassed liquid 3118 exiting the first degas filter 3108 can befurther processed via the optional second degas filter 3110 so as tofurther reduce the amount of gas contained within the liquid. Thereduced pressure level within the first fluid channel 3104, togetherwith the pressure of the degassed liquid 3118 within the second degasfilter 3110, creates a pressure differential across the gas permeablemembrane 3120. The pressure differential serves to force gas from theliquid and gas bubbles side of the permeable membrane 3120 to the gasside of the permeable membrane 3120, where it is transferred to thefirst fluid channel 3104 via conduit 3122. The additionally degassedliquid 3124 exits the second degas filter 3110.

FIG. 12 is a block diagram of the fluidics subsystem of a medicalultrasound system in accordance with an embodiment. The fluidics systemhas a pump control 3136, an optional cooling control 3142, a filter 3140and a fluid level system 3134. The fluid level system 3134 monitors thelevel of fluid in the fluidics system and ensures sufficient fluid ispresent for all fluidic system operations. The filter serves to removeparticulate matter that might clog or negatively impact the system. Thepump circulates the fluid through out the fluidics system. The pumpcontrol 3136 may be the same pump used in an optional degassing assembly3138. Fluid is moved from the base unit to the ultrasound head 3144, andgenerally returns to the base unit in a complete fluid circuit.

The disclosed systems provide a number of advantages. For example, insome embodiments, the disclosed systems can function without a vacuumpump, which avoids the initial and ongoing expenses associated withvacuum pumps (i.e., initial cost of vacuum pump system components andrelated ongoing maintenance/repair costs). It further allows thosesystems to operate without the associated components required tomaintain a degassed fluid environment for the fluid circulation system,further reducing costs and complexity of the fluidics system.

A cross section of a interface cable 400 in accordance with anembodiment is shown in FIG. 13, with an alternate embodiment shown inFIG. 35, the alternate embodiment having similar components. The cable400 has an outer sheath 402. This outer sheath may also provideshielding to the cable to prevent EM radiation from the cable, andphysically protecting the cable. The outer sheath 402 surrounds a firstring of coaxial cables 404 arranged in a circular orientation andsurrounded with an insulation layer 410. A filler layer 412 in theinterior of the interface cable helps with both electrical shielding andwater containment in case of a leak from water lines 414, 416. Thecoaxial cables 404 are used to provide drive signals and receive signalsto/from each element of an array transducer in the treatment head inreal time. If the treatment head does not utilize an array transducer,the coaxial cables 404 are assigned predetermined priority for driving asingle element transducer. In the interior there are power lines 406,407 carrying voltage from the main system 130 to the treatment head 500.The power lines 406, 407 can carry different voltages, while theelectrical components within the therapy head 500 draw power based onone of the two voltages. A ground wire 418 is provided and serves aselectrical ground return for all the electrical components in thetreatment head regardless of the electrical voltage the componentrequires. Information can be relayed between the system base and thetreatment head using two or more twisted pair wires 408, 420. A singletwisted pair can be used (not shown) by multiplexed communication. Inone aspect, the interface cable and the twisted pair wires are EMshielded, to eliminate EM radiation.

Alternatively the interface cable may use two power lines, one for powerand the other for ground. In this embodiment, all components within thetreatment head would use a single voltage, or have an adapter to allowuse of a common voltage. The use of two twisted pair wires are retainedfor serialization of data from base to therapy head, and therapy head tobase (FIG. 34). Alternatively a third two twisted pair may be used toreset/restart the therapy head by cycling power on and off (not shown).

An embodiment of the treatment head 500 is now shown in FIG. 14, notethe form factor and layout of the treatment head may take many forms.The treatment head 500 has an upper section 510 and a removable lowersection 600. The upper section 510 has an indented grip area 502, whichmay be designed for being gripped by left or right handed persons withequal ease. The top of the upper section 510 has a handle guard 504. Thebottom of the lower section 600 has an ultrasound transmission window602. Generally the upper section contains a driver, such as a motordrive unit, and a variety of electronics necessary for the operation ofthe treatment head. The lower section contains an ultrasound transducer.The lower section is considered a “wet” environment, having a fluidsurrounding the transducer, to provide an ultrasound coupling mediumbetween the transducer and the transmission window. The fluid in thelower section may be any low molecular weight solution or liquid havingthe properties of low ultrasound impedance, high thermal mass. The fluidcan be, e.g., water. In one aspect, the liquid is water that issubstantially degassed, chilled and free of impurities (as describedherein). Examples of water solutions for the lower section include, butare not limited to, degassed deionized water, degassed distilled wateror de-gassed filtered water. In an aspect the lower section 600 isdetachable, in the form of a cartridge.

FIG. 15 provides a perspective view of the upper section 510 of anexemplary therapy head 500 with lower section detached. In this view theengagement collar 506 of the upper section is more evident.

An example of one embodiment is shown in FIG. 16. The ultrasound head500 has one or more cables 116 extending from it and going to the mainbody 130. The upper section 510 has a compartment 522 that typically isdry and houses wires, cables, a motor assembly, and/or other featuresfor a transducer, which is mounted in the lower compartment 600. Thelower compartment 600 preferably contains a coupling fluid, such asdegassed water, which allows the transmission of ultrasound energy fromthe transducer to and through a window 602 located near the bottom ofthe lower compartment. Disposed within the upper compartment 510 is anactuation assembly 528. The actuation assembly 528 provides for controlover the position/orientation of the transducer 900 located within thelower compartment 600.

The cable 116 can connect to the top portion 504 of the upper section510. A treatment head controller board is positioned within the uppersection 510 and receives the inputs from the interface cable 116. Thetreatment head control board also has the SERDES chip, and any otherelectronic components needed for the proper operation of the therapyhead. An optional LED or other signal device 512 is provided to indicatethe treatment head 500 is active. An optional trigger 514 is provided soa user may actuate an optional coupling liquid applicator device. Thetop section (the treatment head) has a grip section 502 can be adaptedto be held in either a user's left or right hand.

In operation, a technician rolls the medical ultrasound system 100adjacent to a patient. The technician grasps and moves the ultrasoundtreatment head 500 into the desired position. The ultrasound treatmenthead 500 is aligned so that the window 602 is in contact with thepatient. The user interface device 102 may be operated to generate anappropriate treatment or diagnostic test. During use, the transducermounted in the lower compartment 600 generates ultrasound energy, whichmay be used, for example, for the destruction of adipose tissue, asdescribed in U.S. Published Application No. 2006/0122509, incorporatedherein by reference. The actuation assembly 528 can be used to providefor simplified treatment procedures. For example, the ultrasound head500 can be held in stationary contact with the patient while theactuation assembly 528 varies the position/orientation of the ultrasoundtransducer so as to apply therapeutic treatment to a local region of thepatient using a scan pattern that provides a desired coverage, duration,spacing, etc.

As shown in FIG. 16, the therapy head 500 includes a lower compartment600, or cartridge, and a therapy head body, or upper compartment 510.Although the upper compartment 510 is described as a “compartment,”suggesting a hollow body, the compartment may contain many structures.In an embodiment, the upper compartment 510 houses operationalcomponents of the therapy head 500. The inside of the upper compartment510 is usually dry and houses wires, cables, a motor assembly,electronics, and/or other features for a transducer 900 (FIG. 17), whichis mounted in the lower compartment 600. In addition to the transducer900, the lower compartment 600 preferably contains a fluid, such asdegassed water 604, used to couple ultrasound energy from the transducer900 to and through a flexible window 602 located near the bottom of thelower compartment.

The transducer 900 mounted in the lower compartment 600 may take variousdifferent forms and, in an embodiment, is movable so that it may focustoward various different locations of the window 602. An example of atransducer and movement system are described in commonly owned U.S.patent application Ser. No. 12/364,327, filed Feb. 2, 2009, and entitled“Therapy Head For Use With Ultrasound System.” Other transducers and/ormovement systems may be used. A transducer may also be fixed in thelower compartment 600.

FIG. 17 illustrates internal assemblies of a therapy head 500 similar tothat shown in FIG. 16. Mounted within the upper compartment 510 is theactuation assembly 528. The actuation assembly 528 is coupled with anultrasound transducer assembly 900 by way of a control arm 532. Thecontrol arm 532 may be configured to interface with and pivot within areceptacle 534 that is coupled with a partition that separates the uppercompartment 510 from the lower compartment 600. In one aspect, the lowercompartment 600 can be disengaged from the upper compartment 510. Thelower compartment 600 is typically a sealed assembly that contains acoupling fluid, such as degassed water, that is used to transferultrasound energy transmitted by the transducer assembly 900. Thereceptacle 534 includes at least one fluid seal to prevent fluid fromentering the upper compartment 510 from the lower compartment 600 whenthe two compartments are joined together. The seal may be one or moreO-ring(s) around a spherical joint of the control arm 532. The controlarm 532 includes a control arm upper end 536 disposed within the uppercompartment 510. In the position/orientation shown, the ultrasoundtransducer assembly 900 is shown as transmitting focused ultrasoundenergy through the window 602 as illustrated by the ultrasound energyprofile 610.

The actuation assembly 528 is operable to move the control arm upper end536 so as to pivot the control arm 532 within the receptacle 534. Therange of motion of the actuation assembly and the control arm 532produces a coverage area 610 within which focused ultrasound energy canbe directed in a controlled fashion (e.g., by using scanning patterns,scanning rates, energy transmission levels, etc.). When the lowercompartment 600 is engaged to the upper compartment 510, the transducerassembly 900 is mechanically engaged to the control arm 532 through acontrol arm receptacle 548. Thus as the control arm 532 is moved by theactuation assembly 528, the transducer is moved in direct relation tothe control arm 532.

In an embodiment, it is also possible for the receptacle 548 to move ina reciprocal fashion relative to the movement of the control arm 532.The movement of the receptacle 548 relative to the control arm 532 ismerely a design choice feature which may be adjusted according to desirebased on the intended range of motion, and adapting any positiontracking and/or position sensor information gathered about the positionof the transducer assembly 900.

The actuation assembly 528 according to an embodiment has a modifiedlead screw 548 (available from Haydon Kerk Motion Solutions, Inc., KerkProducts Division, 1 Kerk Drive, Hollis, N.H. 03049) with a pair ofmotors 556, 558 working to drive a carriage nut 546 over the screw rail.The motors 520, 530 may operate through a set of gears 560 to drive thescrew rail. A carriage nut coupler 544 is moved by the actuationassembly 528 to drive the motion of the upper arm 536. The motion may bedirect, reciprocal or any relation suitable for the movement of thetransducer assembly 540. A union joint 535 connects the control arm 536to the carriage nut coupler 544.

The lower compartment 600 may also feature a pressure compensator 690 toadapt the fluid pressure in the lower compartment 600 to variations inatmospheric pressure during use or shipment.

A perspective view of the upper compartment 510 or treatment head withfocus on the connector for the upper compartment and lower compartmentis shown in FIG. 18. The upper compartment 510 has a recess 554 formechanically engaging the cartridge. The TEC layer 744 is shown where itwill abut the corresponding section of the lower compartment having theriser 772 or heat transfer plate 748. A control arm 578 for engaging andcontrolling the corresponding cartridge component for moving thetransducer assembly is also shown. An electrical interface 638 is alsoprovided for handling the various electrical interfaces required toproperly control the transducer assembly, and monitor any sensorsdesired in the cartridge.

In an embodiment, a cooling device 750 is affixed directly to the lowercompartment 600 of the treatment head (See FIG. 19). A cooling device750 is positioned to remove heat from the lower compartment 600 anddissipate heat either into the upper compartment 510, or to the exteriorenvironment (outside the system). The cooling device 750 typically has ahigh capacity for heat transfer, and is also typically able to absorband dissipate heat quickly. The cooling device 750 may be a stand alonedevice in the treatment head, or work in conjunction with a system inthe base unit, such as a fluid circulations system 208. The fluidcirculation system 208 may form a circuit with the cooling device 750 toform a cooling circuit 700, and have conduits for sending fluid to thetreatment head 704, 706 and conduits for receiving fluid from thetreatment head 703, 705. In one aspect the cooling circuit 700 alsoincludes a chiller for removing heat from the fluid as it circulatesinto the system base from the treatment head. The fluid circulationsystem 700 may also have a fluid degas unit 300 as previously described.

In accordance with an embodiment, instead of circulating water through acartridge of a therapy head, the lower compartment 600 is a sealedstructure that includes the transducer 900 mounted therein. Acompartment fluid 604, such as degassed water, surrounds the transducerassembly 900, and is sealed in the lower compartment 600 with thetransducer assembly 900. The sealed lower compartment 600 is removableand replaceable, as a single unit with the coupling fluid 604 and thetransducer 900. Thus, a technician does not have to break a seal orremove a transducer 900 from the fluid 604. Instead, a user may removethe cartridge 600 at any time, such as at the end of the useful life ofthe transducer assembly 900, then a new lower compartment 600 with a newtransducer 900 sealed inside fluid 604 replaces the previous lowercompartment cartridge 600.

In one aspect the fluid in a sealed cartridge may be degassed down to alevel of 10 PPM dissolved oxygen or less. Dissolved oxygen may be usedto measure the concentration of dissolved gasses because degassingoperations tend to remove all dissolved gasses in equal proportion. Theratio of oxygen to other gasses is fairly constant, so reducing theoxygen content of a fluid also reduces the gas content of all othergases in the same ratio or proportion. The actual level of dissolved gascontent that the fluid in the cartridge can tolerate before the acousticpath is adversely affected depends on the intensity of the ultrasoundenergy, the focal length of the transducer (either mechanically orelectronically focused), the pulse repetition frequency (PRF) as well asother components of determining the transducers operation. Generally thecombination of these electronic and power considerations can be balancedto allow a higher level of dissolved gases. If the transducer isoperating at power and performance factors where dissolved gases aremore likely to cause problems in the sealed environment (for example, byproducing cavitation or micro streaming effects) then the dissolved gaslevel may be lowered to reduce or eliminate these negative effects.Generally a desired level of dissolved oxygen to achieve in a sealedtransducer cartridge is less than 10 PPM. In many aspects, levels may bemaintained at around 5 PPM.

The lower compartment 600 includes a profile that fits to a profile ofthe upper compartment 510 so that the two components may be removablyattached to one another. If desired, a latch or other lock may beprovided to releasably lock the two attached components. A tool may beused to assist in the removal of the cartridge 600 and the upper section510 of the treatment head 500, or to assemble the two components into aworking treatment head 500.

The transducer assembly 900 may generate heat during use, heating thefluid 604 (FIG. 20). In accordance with an embodiment, a cooling device750 is provided for cooling of the fluid 604 sealed in the lowercompartment 600. In an embodiment, the cooling device 750 includes athermoelectric device 744, but other devices may be used. As is known, athermoelectric device, such as the thermoelectric device 744, isdesigned so that electric voltage is converted to a temperaturedifference across the thermoelectric device. The temperature differenceresults in a cold side and hot side of the thermoelectric device 744. Inthe diagram shown in FIG. 20, the bottom side of the thermoelectricdevice 744 is a cold side, and the top side is a hot side. Thethermoelectric device 744 is connected to a power source 204, such as abattery, an AC/DC converter, or another suitable power source, forproviding voltage to the thermoelectric device 744. The power source 204may be mounted within the therapy head or may be connected via wiresfrom another location, such as the base unit 130. As electric voltage isprovided by the power source 204, a temperature differential is createdacross the thermoelectric device 744, creating the cold and hot sides.

In the embodiment shown in FIG. 20, a heat transfer plate 748 ispositioned between a cold side of the thermoelectric device 744 and thefluid 604. The heat transfer plate 748 is utilized to remove heat fromthe fluid 604 and transfer the heat to the cold side of thethermoelectric device 744.

A structure for removing heat from the thermoelectric device 744 may beattached to the hot side of the thermoelectric device 744. In theembodiment shown in the drawings, this structure is a heat exchanger752. The heat exchanger 752 includes at least one fluid in conduit 706and at least one fluid out conduit 705. The heat exchanger 752 may be,for example, a manifold with a serpentine or parallel fluid paththrough, although other structures or methods for heat removal may beused.

In an embodiment, the thermoelectric chip layer 744 includes one or morethermal electric chip(s) (TEC). Multiple chips may be placed in an arrayto transfer heat from the lower compartment 600 (for example, TEC chipsmay include MELCORE CP1.0-63-05L 16.6 watt TECs (Melcore, 1040 SpruceSt., Trenton, N.J. 08648)). As described below, these TECs may bepermanently or releasably attached to the components that remove heatfrom the lower compartment 600. A lower heat transfer plate 748 can bebonded to the lower compartment 600, and absorbs heat from the lowercompartment 600 either by thermal convection from the lower compartment600, as through a heat sink or heat transfer plate 748, or by being indirect physical contact with the fluid solution 604 within the lowercompartment 600. In the latter case, the heat transfer plate 748 isfitted into the compartment wall of the lower compartment 600. When thelower compartment 600 is attached to the upper compartment 510, thelower heat transfer plate 748 is releasably connected to the TEC layer744. The TEC layer 744 has power from a power supply 204. Proper use ofthe TEC allows a thermal gradient to be established in the TEC so thecool side of the TEC faces the lower heat transfer plate 748. Heatabsorbed from the lower compartment fluid 604 is transferred to the TECthrough the coupling agent between the lower heat transfer plate 748 andthe TEC layer 744. The thermal coupling material between the TEC andlower compartment heat transfer plate is a material such as grease orgel that allows for good thermal contact between the two layers, butdoes not form any permanent bond, thus allowing for releasableengagement of the TEC from the lower compartment on demand.

The TEC layer 744 can be bonded in a more permanent fashion to the upperheat transfer layer 752, by way of a thermally conductive epoxy orresin. The upper heat transfer layer 752 has a water basin for watercirculation from the base unit. A fluid circulation system 208 pumpswater through the fluid conduits 704, 706, with at least one line comingfrom the base unit 130 and going into the upper thermal transfer layer752, while the other conduit brings warm fluid back to the fluidcirculation system 208. As previously described, the fluid circulationsystem can include a chiller, so the warm fluid returning to the baseunit is chilled prior to being pumped back to the thermal transfer layer752. The heat exchanger 752 may be a manifold that is arranged to permita cooling fluid, such as water, to flow through. The fluid enters theinlet conduit 706 and exits via the outlet conduit 705. The flow offluid through the heat exchanger removes heat from the heat exchanger752, which in turn removes heat from the hot side of the thermoelectricdevice 744.

As discussed above, the lower compartment 600 may be replaceable as aunit, with the fluid 604 of the lower compartment being in a closedsystem that is never opened by a user, even during replacement of thecartridge/lower compartment 600. An example of the removable lowercompartment 600 is shown in FIG. 21. In this embodiment, a flange 646extends upward from the lower compartment 600 and is removablyattachable to a lower surface of the upper compartment. The portion ofthe lower compartment 600 used to engage the upper compartment is shownhaving a recess 662 where the lower compartment heat transfer plate 748is fitted with a form fitting riser 772 to fit in the recess 662. Theform fitting riser 772 may form a flush or recessed fit in the recess662 when assembled. When the lower compartment 600 is attached to theupper compartment, the TEC layer lines up with and is coupled to theheat transfer layer 748 via the form fitting riser 772. In theembodiments shown in FIGS. 21-25, the thermoelectric device is connecteddirectly to the heat exchanger using a releasable heat transfermaterial, such as heat transfer grease, pad or gels. Note the lowercompartment heat transfer plate may be permanently bonded to the TEClayer using an epoxy if the lower compartment is adapted to fit to thelower heat transfer plate instead of the TEC layer when the lowercompartment and upper compartment are engaged.

An exploded view of the major component stacks of an exemplary systemare shown in FIG. 22. Here the TEC layer 744 is integrated into thebottom section of the upper compartment. The heat transfer plate 748 mayextend along a top surface of the fluid 604 to provide large area ofcontact between the heat transfer plate and the fluid 604. The heattransfer plate 748 includes a central opening 770. The opening 770 isdesigned to receive a controller mechanism for movement of thetransducer assembly 900, as described in application Ser. No.12/364,327, cited above. A heat transfer plate riser 772 is included onone side of the heat transfer plate 748 and extends upward into theaperture 662.

The thermoelectric device 744 is attached to the top of the riser 772,for example, as described above, by a heat transfer material (shown bythe reference numeral 780 in FIG. 23) or other suitable adhesive orstructure that is thermally conductive. The heat transfer material 780between the thermoelectric device 744 and the top of the heat transferplate riser 772 maintains a thermally conductive bond between the riser772 and the thermoelectric device 744 but, in an embodiment, isreleasable. As an example, the heat transfer material 780 may be held inplace through capillary attraction when the lower compartment isconnected to the upper compartment. Some adhesion may be provided tomake a solid bond between the components, but the bond is preferablyreleasable. If a permanent bond is desired, the heat transfer materialmay be an epoxy. If a releasable option is desired, the heat transfermaterial can be a pad or grease.

Similarly, the heat exchanger 752 is attached to the hot side of thethermoelectric device 744 by a second heat transfer material 782 orother suitable heat conductive connecting structure. The bond here isalso thermally conductive. The heat transfer material 782 in the uppersection 510 can be an epoxy or other permanent bonding material.

The fluid circulation system 208 (FIG. 20) is positioned, for example,in the base 130. The fluid circulation system 208 pumps a fluid, such astemperature controlled water, in a circuit between the pump and the heatexchanger 752. The fluid from the pump flows in the inlet 706 and out ofthe outlet 705. In an embodiment, conduits 703, 705 between the fluidcirculation system 208 and the heat exchanger 752 are thermallyconductive so that heat removed by the water from the heat exchanger 752dissipates as the water travels on the round trip from the heatexchanger, through the pump, and back to the heat exchanger. As such, achiller may not be needed to remove heat from the water. Instead, thethermal loss of the system results in the water being cooled beforereturning to the heat exchanger 752. If the fluid is chilled, the outletroute 705 and pump input line 703 may be thermally conductive, whileoutflow pump line 704 and treatment head inlet 706 are thermallyinsulated. Note that while one pair of conduits is designated as theinlet pair and the other as the outlet pair, the conduits are generic inthe sense that the flow direction can be reversed, so long as fluidflows in a circuit between the water circulation system in the base andthe treatment head.

The use of a chiller or thermally conductive lines will depend largelyon the amount of heat needed to be removed from the cartridge 600. Ifthe transducer assembly operates in a mode where virtually no heat isgenerated (for instance, in a low pulse repetition frequency diagnosticmode), then thermally conductive conduits would be amply sufficient tokeep the temperature state of the cartridge at a desired constant level.However if the transducer were operated in a very high power therapeuticmode, the amount of heat build up in the cartridge 600, and thus thecartridge internal degassed water 604 would be high enough to requirethe use of chilled fluid to help draw off the heat through the coolingdevice 750. In one aspect the system is equipped with both thermallyconductive fluid conduits where needed, and a chiller as part of thefluid circulation system 208. That way the system may automaticallyregulate the use of the chiller based on thermal temperatures detectedin the lower compartment 600. Detection could be achieved through theuse of heat sensors in the lower compartment 600, bathed in the couplingfluid 604, or able to sense the temperature of the heat transfer plate748. Optionally the chiller in the fluid circulation system may bemanually controlled.

The temperature of the lower compartment/cartridge 600 may also be usedto reduce a patient's skin sensation. Similar to the use of a cold packto reduce pain, the cartridge may be regulated to achieve a low enoughtemperature to reduce skin sensitivity to therapeutic ultrasoundtreatments.

As described above, the lower compartment 600 is a sealed system thatcontains the transducer assembly 900, the transducer fluid 604, and theheat transfer plate 748. This sealed system may be removed by removingthe lower compartment 600 from the therapy head 500. During removal, thetemporary or releasable adhesive (e.g., the heat transfer material 780),allows release of the heat transfer plate 748 from the thermoelectricdevice 744. In this manner, the heat transfer plate 748 releases fromthe thermoelectric device 744 when the lower compartment 600 is removedfrom the upper compartment 510, allowing the thermoelectric device 744and the heat exchanger 752 to remain in the upper compartment 510 whenthe lower compartment 600 is removed and replaced. Alternatively, thesepieces may remain attached to the lower compartment 600 and may bereplaced as well, but, by leaving the thermoelectric device 744 and theheat exchanger 752 within the upper compartment 510, no detachment orother reconfiguration of wiring for the thermoelectric device 744 orfluid input or output for the heat exchanger 752 is required. Inaddition, because these components remain in the upper compartment, theexpense of replacing them is avoided.

During the treatment process, the transducer assembly 900 generatesheat. If the transducer assembly 900 is overheated, damage to thetransducer may occur. In the embodiment of the therapy head 500 shown inthe drawings, the heat of the transducer assembly 900 is dissipated inthe fluid 604. This heat, in turn, is removed so that cooling maycontinue and/or so that the therapy head 500 does not become too hot todamage the transducer or to be placed against a patient. In accordancewith an embodiment, the thermoelectric device 744 is used to remove heatfrom the fluid 604 so that overheating is not an issue.

During operation of the therapy head, the power supply 204 suppliesvoltage to the thermoelectric device 744, which generates a heatdifferential between the thermoelectric device's hot side (upper side inFIG. 20) and its cold side (the downward side). The thermal electricdevice can be selected based on the amount of cooling wattage desired tobe removed from the system, and the capacity for the fluid coolingsystem to remove the corresponding cooling wattage from the thermalelectric device representing the cooling wattage cooled from the lowercompartment 600, and the amount of electrical wattage put into thethermal electric device to achieve the desired cooling from the lowercompartment. Because thermal electric device cooling is not 100%efficient, the fluid cooling heat exchanger connected to the thermalelectric cooling device in the upper compartment 510 of the therapy head500, typically is able to remove the combined thermal wattage of thecooling wattage from the lower compartment 600 and electrical wattageinput into the thermal electric device to achieve the desired coolingwattage. For example, if in application the thermal electric devicerequires 10 electrical watts to achieve 6 cooling watts then the heatexchanger cooling system should be capable of removing 16 thermal wattsthrough the hot side of the thermoelectric device to achieve the desired6 watts of cooling. While this system is not as efficient as directcooling of the lower compartment, it does allow the lower compartment toremain completely sealed, which provides additional benefits and ease ofuse.

In an embodiment using TEC devices, multiple TECs can be desirable toremove more heat rather than a single large TEC. Larger devices may havea diminishing return on efficiency, higher thermal transfer efficiencymay be maintained by using smaller wattage drawing TECs. Thus the TEClayer may have numerous TEC devices arranged in a flat pattern. The heattransfer plate 748 could abut all the TEC devices arranged in the TEClayer. Likewise the heat transfer device 752 of the upper compartmentwould abut all the upper surfaces of the TEC layer simultaneously. Thesize, pattern and energy draw of the TEC layer 744 may varysubstantially. Though a rectangular recess 662 is shown for receivingthe TEC layer, the recess may be any size or shape to accommodate theTEC layer. The layer (and recess) orientation need not be horizontal,and a combination of multiple recess/aperture ports may be used to matewith multiple TEC layers distributed around the interface between theupper compartment 510 and the cartridge 600. The physical limit of theupper compartment 510 that interfaces with the recess 662 can be the TEClayer 744.

To remove heat from the hot side of the thermoelectric device 744, thefluid circulation system 208 has a pump to pump a fluid, such as water,through the heat exchanger 752. The water takes a serpentine path orparallel path through the heat exchanger 752 and removes heat as itflows through the heat exchanger. As such, the cold side of thethermoelectric device 744 constantly removes heat from the sealeddegassed water 604 in the lower compartment 600. In this manner, thelower compartment 600 may be maintained at a desired temperature. Theheat in the heat exchanger water is removed through the thermal lossesin the system, or may be removed in another manner, such as a downstreamchiller. However, by using thermal losses in the conduits, passivecooling occurs, and additional heat removal devices are not required. Assuch, the passive cooling by the conduits to and from the circulationsystem 208 reduces expense and eliminates maintenance issues withrespect to a chiller or other active cooling system.

When a user desires to replace the lower compartment 600, the heattransfer plate 748 is removed with the lower compartment 600, and thethermoelectric device 744 and everything above it remain attached to theupper compartment 510. Another lower compartment 600 may then beattached to the upper compartment 510, and then the therapy head 500 isready for use again.

An illustration showing the fully assembled lower compartment heattransfer stack with heat transfer plate 748, riser 772 and thermalconductive material 780 is shown on the bottom of FIG. 24. The top ofFIG. 24 shows the fully assembled upper compartment heat absorbing andliquid heat sink stack. FIG. 25 provides an illustration of the entireheat transfer stack using a TEC layer.

In an embodiment (FIG. 26), a heat transfer plate 748 extends across thetop and part of the way down the sides of a lower compartment 600,forming an inverted bowl structure. In this embodiment, the heattransfer plate 748 is in contact with a lower-compartment fluid, such asdegassed water (disposed within the lower compartment 600), across thetop and part way down the sides of the lower compartment 600, therebyincreasing the surface area through which heat can be transferred fromthe lower-compartment fluid into the heat transfer plate 748. Theinverted bowl shaped heat transfer plate 748 may be a component of aremovable/replaceable lower compartment 600. In the embodiment shown,the heat transfer plate 748 has a top surface 695 that is in contactwith the lower-compartment fluid, and peripheral exterior plates 698that are in contact with the lower-compartment fluid and form part ofthe exterior of the lower compartment 600. Top surface 695 and exteriorplates 698 can be thermally conductive so that they may transfer heat tothe surrounding air, or they can be externally insulated to avoidpresenting a hot external surface. In an embodiment, the heat transferplate 748 includes a top surface and partial side plates (not shown)disposed within the lower-compartment fluid. With partial side platesdisposed within the lower-compartment fluid, the lower-compartment fluidis contacted with both surfaces of the partial side plates, whichresults in increased contact surface area between the heat transferplate 748 and the lower-compartment fluid. This increased contactsurface area may help to increase the heat transfer rate between theheat transfer plate 748 and the lower-compartment fluid. Partial sideplates disposed within the lower-compartment fluid can include fluidopenings and/or channels to facilitate the flow of the lower-compartmentfluid over these submerged partial side plates. The cold side of athermoelectric device 744 can be attached to the top of the heattransfer plate 748 by a heat transfer material 780 and a heat exchanger752 can be attached to the hot side of the thermoelectric device 744 bya heat transfer material 782.

The lower-compartment fluid is “stirred” by acoustic pressure when thetransducer (disposed within the lower compartment 600) is active. This“stirring” may be sufficient to constantly circulate within thecartridge, and thereby make contact with the heat exchanging components.The cooled lower-compartment fluid tends to sink into the lower portionof the lower compartment 600. The combination of the rising fluid heatedby the transducer and the sinking fluid cooled by the heat transferplate may result in a convective current that helps to enhance the rateof heat transfer between the transducer and the lower-compartment fluidand between the lower-compartment fluid and the heat transfer plate 748.This convection current may be further enhanced by the cooling of thelower-compartment fluid that occurs due to contact with the partialsidewalls of the heat transfer plate 748 on account of resultingperipheral sinking of the cooled lower-compartment fluid, which maycomplement the central rising of the lower-compartment fluid that isheated by a centrally located transducer. Additionally, the increasedcontact area between the heat transfer plate 748 and thelower-compartment fluid may also help to maintain the lower-compartmentfluid at a lower equilibrium temperature.

In an embodiment, the heat exchange process is done by circulating fluidfrom the fluid circulation system 208 into the cartridge 600 withoutcompromising the integrity of the fluid sealed in the cartridge (FIG.27A). A heat exchanger 750 can be positioned within the lowercompartment 600 so as to absorb heat from a lower-compartment fluid 604.The first heat exchanger 750 is physically connected to a fluid circuit706, 705 so temperature controlled fluid from the fluid control circuit208 can take heat from the lower compartment fluid 604.

The first heat exchanger 750 is a fluid-circulating heat exchanger thatis in fluid communication with the fluid circulation circuit 208 whichcontains a fluid chiller (not shown). In an embodiment, the first heatexchanger 750 are removed with, the lower compartment 600. A pump (notshown) can be used to circulate a fluid (e.g., water) between the firstheat exchanger 750 and the chiller in the fluid circulation system 208.

Various configurations can be used for the first heat exchanger 750. Thefirst heat exchanger 750 can be made from a thermally conductive metal(e.g., brass, copper, aluminum, etc.). The first heat exchanger 750 canalso be shaped to maximize its surface area for more effective heattransfer. Such shapes are well known in the art for cooling, and includecommon shapes like baffles, coils or other repeating patterns.

The use of a first heat exchanger 750 can provide a number ofadvantages. For example, as described above, the first heat exchanger750 can be located so as to facilitate circulation of thelower-compartment fluid, thereby helping to increase heat transfer.Additionally, the first heat exchanger 750 can be configured to increaseand/or maximize the amount of surface area contact with thelower-compartment fluid, thereby helping to increase heat transfer.

The chiller can be located at a variety of locations within the baseunit. In one aspect the chiller is located along with the rest of thefluid circulation system 208. If the chiller is not positioned inphysical proximity to the fluid circulation system, it is stillconsidered part of the system 208. Alternatively, the heat exchanger 750may be positioned within the upper compartment 510 in a manner thatallows for cooling in a circuit involving components only inside thetherapy head 500. Such an embodiment may include a air cooled heat sinkand fans to ensure air flow moves over the heat sink in a continuousmanner.

FIG. 28 shows a lower compartment 600 for a therapy head 500 (FIG. 14)in accordance with an alternative embodiment. The front or lower lensincludes a window 602 (best shown in FIG. 29A) and sides 614.

FIG. 30 shows another embodiment where the fluid from the lowercompartment is circulated into the upper compartment to a heatdissipating unit 750 which may include a heat sink with a plurality ofheat radiating elements (similar to heat sinks used for computer centralprocessor unit (CPU) chips). The heat sink may have a fan for directingair over the heat sink, or be encased in a fluid bath and cooled usingfluid from the fluid circulation system 208. In one aspect the fluidused for cooling purposes is water.

The lower compartment 600 includes a transducer assembly 900 mountedtherein and having a ball joint 608. The ball joint 608 is part of apivot mechanism 610, such as is described in U.S. patent applicationSer. No. 12/364,327, cited above. An opening 612 is located at the endof a shaft 613 for the transducer assembly 900.

The lower compartment 600 includes a heat exchanger 614 that extendsalong the inside of the side walls 603 for the lower compartment 600.The heat exchanger 614 is preferably formed of a highly thermallyconductive material, such as copper. In the embodiment shown in thedrawings, the heat exchanger 614 includes two sets of tubes that extendin a serpentine path around a perimeter of the lower compartment 600,inside the side walls 603. In an embodiment, the heat exchanger 614 isarranged so that it maximizes space on the outer portions of the lowercompartment 600, but is outside the range of movement of the transducerassembly 600. In one aspect, the cooling system 700 is able to remove asmany cooling watts from the cartridge 600 as necessary to maintain adesired operational temperature. If the transducer assembly is operatingat high power and the transducer fluid 604 gets hot, the cooling wattsto remove may be as high as 60 cooling watts. The desired temperature inthe cartridge and the arrangement and type of TEC devices are balancedto ensure the cooling range is obtained. Although some instances mayrequire high cooling watts, the system can operate by removing 15-20cooling watts. In this case both chilled water and an appropriate flowrate may be used to maintain the cartridge temperature between 1-37° C.The temperature in the cartridge may be adjusted by the user. Ifdesired, a TEC configuration can be used in combination with a fluidbaffle configuration (not shown).

The heat exchanger 614 includes an inlet conduit 616 and an outletconduit 618. The inlet and outlet conduits 616, 618 are mounted to ballseals 620, 622 and include valve fittings 624, 626. The seals 620, 622are mounted in a top-plate 630 of the lower compartment 600. Thetop-plate 630 includes a central opening 632 through which the shaft 613extends. An O-ring 634 is mounted in the opening and seats against theball joint 608. The shaft 613 and the ball joint form a bearing memberthat fits in the central opening 632. The O-ring 634 permits thetransducer assembly 900 to pivot as described in U.S. patent applicationSer. No. 12/364,327, and prevents leaking of fluid out of the lowercompartment 600 at the opening 632. A pivot top 636 fits over the O-ring634. The ball joint 608 is captured between the pivot top 636 and theinner rim of the opening 632.

An electrical connector 638 is positioned on one side of the top plate630. Wires may run from the electrical connector 638 to the transducerassembly 900. In addition, the electrical connector 638 may beconfigured to receive a wiring harness or other electrical connectionsthat lead from the upper compartment. In an alternate embodiment, thewires for the transducer assembly 900 may extend along or down the shaft613, or may be routed in another manner. The electrical connector 638 ispreferably a quick disconnect connector and connects to a wiring harnessor other connector (not shown) that is attached to the therapy head.When the wiring harness is attached to the connector 638, power, such asfor the HIFU transducer drive or for other electronics in the transducerassembly, or communication signals may be supplied to the transducerassembly 900 via the wiring circuit.

Optionally, an alignment post 640 is positioned on one location of thetop plate 630. The alignment post 640 permits an installer to properlyalign the lower compartment 600 with an upper compartment of the therapyhead during installation. A bubble trap 642 may be provided for thecapture of bubbles formed inside the lower compartment 600. In anembodiment, a micro valve 644 is attached to the bubble trap 642 toisolate bubbles away from the acoustic path of the transducer. The microvalve may be mounted in the alignment post 640.

The lower compartment 600 can be sealed, with the acoustic window 602,the sides 603, and the top-plate 630 forming an enclosure. A couplingfluid, such as water is captured in the enclosure, and the enclosure ispermanently sealed. To prevent gas seepage, the portions forming theenclosure can be treated with a material to prevent gas leakage into thelower compartment. The enclosure interior may be treated with a sealant,or metallization layer, such as sputtered titanium. The heat exchanger614 extends around the perimeter of this enclosure and provides optimalheat convection because of its serpentine or parallel pathconfiguration, the large amount of surface area provided by extendingthe heat exchanger 614 around the perimeter, and by utilizing the dualconduit arrangement.

As with earlier embodiments, water is circulated through the heatexchanger 614 via the inlet conduit 616 and the outlet conduit 618. Thiswater may be circulated, for example, to a base unit for cooling, or maybe attached to a thermoelectric cooler for cooling, or may be routedthrough a conduit with inefficient heat retention that results in heatloss, as described in earlier embodiments.

FIG. 29B is an bottom, isometric view of a top portion of a transducercartridge displaying an alternative fluid conduit 614A in accordancewith an embodiment. Instead of the serpentine shape that is used for theconduit 614, the conduit wraps around an inside portion of the top plate630. Otherwise, the cartridge is the same in configuration. Many othershapes can be used for the conduit.

The therapy head 500 includes a body, such as an upper compartment 510,including an indentation 502 for fitting a user's hand (FIG. 37). Theupper compartment 510 may be attached to an arm and/or may include wiresor conduits that lead to a base unit.

FIG. 27B is a bottom perspective view of an exemplary upper compartment510, with the lower compartment 600 removed. The upper compartment 510includes a recess 554 for receiving the lower compartment 600. Anelectrical connector 538 is positioned in the recess 554.

An opening 558 is located in the recess 554. Two fluid connectors 560,562 are positioned on opposite corners of the recess 554. These fluidconnectors 560, 562 lead, for example, to a thermoelectric cooler, achiller in the base unit, conduits that provide a cooling effect bybeing thermally inefficient, or some other cooling structure orconfiguration.

A control arm 578 for a driving mechanism, such as is described in U.S.patent application Ser. No. 12/364,327, is centrally positioned in therecess 554. The angle of the control arm 578 may be determined by theposition of the driving mechanism.

To attach the lower compartment 600 to an upper compartment 510 of atherapy head, the wiring harness or recess 554 that is connected to theupper compartment is connected to the electrical connector 538. If awiring harness is used, it is connected first. If a stationaryconnector, such as the recess 554, is used, then the connector isconnected to the electrical connector 538 as the lower compartment 600is attached to the upper compartment 510.

In any event, to attach the lower compartment 600 to the uppercompartment 510, the top plate 630 of the lower compartment 600 isfitted into the recess 554 of the upper compartment. To allow thisfitting, two fluid ports 620, 622 are aligned to the corresponding fluidports 560, 562 in the upper compartment 510. An optional guide post 640is aligned with the corresponding female structure in the uppercompartment, for example the opening 558. The fluid ports 620, 622 mayuse seals to align with and connect to the fluid connectors 560, 562 onthe upper compartment 510. During alignment, the opening 612 on theshaft 613 is aligned with the control arm 578 on the bottom of the uppercompartment 510. The control arm 578 may have to be centered for properalignment. To this end, a “home” operation may be provided for centeringthe control arm 578. This control arm 578 is connected to the actuatorassembly in the upper compartment, and the transducer assembly 900 inthe lower compartment (when the upper and lower compartments areproperly combined) such that, once installed, the movement of thecontrol arm causes the desired movement of the transducer assembly 900.

After alignment, lower compartment 600 is pressed into the uppercompartment 510. The two profiles of the lower compartment top plate 630and the upper compartment recess 554 fit together. The electricalconnector 538 seats onto the corresponding lower compartment electricalconnector 638. The mechanical linkage 578 engages the transducer armassembly 612. If fluid connectors are used, the fluid lines 560, 562connect to the seals 620, 622. Appropriate valves are provided to openor close the fluid connectors. The nub 578 fits into the opening 612 ofthe shaft 613. The therapy head 500 is now ready for operation.

Once connected, cooling water may flow into and out of the heatexchanger 614 via the fluid connectors 560, 562. The direction of thetransducer assembly 900 may be changed by using the drive mechanism, viathe attachment of the nub 578 and the opening 612. The transducerassembly 900 may be provided power via the connectors 538, 638.

Disconnecting the lower compartment 600 is done in reverse order. Thatis, the lower compartment 600 is disconnected from the uppercompartment. If desired, a latch or other lock mechanism may be providedfor maintaining connection of the lower compartment 600 to the uppercompartment 510. As an alternative, the connection of the variouscomponents of the lower compartment 600 to the appropriate components ofthe upper compartment, such as the seals 620, 622 to the fluidconnectors 560, 562, may provide a sufficient holding force to keep thelower compartment 600 in place. Connecting and disconnecting the lowercompartment from the upper compartment may be facilitated by the use ofa tool.

In accordance with an embodiment, a mechanical compensator may beprovided for the lower compartment 600 as shown in FIGS. 32A-B, 33A-B.This mechanical compensator can be configured to offset pressure changesin the environment in which the therapy head is operated, for example,changes in pressure due to altitude, and to accommodate pressure changesin shipping the cartridge and/or accommodate any water loss over time.

The mechanical compensator may take a variety of forms. Any device thatadjusts for changes in pressure and maintains the desired degas state ofthe internal fluid may be used. In an embodiment, a passive compensatorhas a body 680 containing closed piston face 686 and a spring 684 (FIG.32A). The closed piston face 686 has an opening 688 exposed to the fluidfilled interior of the lower compartment/transducer cartridge 600. Thecartridge ships with the full water volume and as the internal watervolume expands (due to internal temperature increase or externalpressure decrease) the piston face 686 deflects backwards against thespring 684 allowing the internal volume to expand (FIG. 32B). Once thetemperature or pressure returns to normal, the spring force pushes thepiston forward returning the volume back to initial equilibrium. Theback of the piston is vented to the atmosphere. Other examples ofpassive compensators include metal bellows, an air filled bladder(having the air sealed from the fluid), a compressible material likefoam or soft durometer rubber component, or an expandable outer housing.

In an embodiment, and active compensator 690 may be used. An activecompensator could tap off of the cooling water in the heat exchanger tooperate the compensator. The compensator would consist of a housing 692,a piston 694 and a one way valve 696. The cartridge ships under-filledby the volume of the compensator with the internal piston in theretracted position (FIG. 33A). Once the cartridge is installed and thesystem turned on, the pressure of the cooling water would drive thepiston outward to force the volume increase. The piston could be sizedto reduce the pressure so that the piston extension would stop when thepressures equalized (Example: Cooling water at 20 PSI and internalpressure desired to be 2 PSI then the piston area could be reduced10:1)(FIG. 33B). The one way valve would allow the piston to expand butnot contract thereby maintaining the pressure in the cartridge. Otherembodiments of an active compensator include a flexible bladder, amechanical piston or a user applied syringe. Additional embodiments arereadily available and well understood by those skilled in the art.

In an embodiment, the inner surfaces of the cartridge 604 (FIG. 31) mayinclude a thin inner coating 601 to prevent gas permeability. Forexample, if the sides 604, window 602 and top plate 630 are made ofplastic, a titanium base layer may be provided to prevent atmosphericgas from entering the chamber and dissolving in the fluid inside. Thislayer may be attached in a suitable manner, but in an embodiment istitanium that is sputtered between approximately 500 to 1500 angstromsthick onto the inside surfaces of the cartridge. Alternatively themetallization layer may be copper and nickel, or any other materialsuitable to fill pores in the plastic chamber and prevent gas fromentering the chamber. Any material may be used for this purpose thatsatisfies the requirements of being insolvent in the liquid (thematerial will not enter into solution in any appreciable amount) and thematerial reduces gas permeability through the chamber material to anacceptable level. In one aspect, the dissolved oxygen (DO) content iskept below about 10 ppm. In another aspect the DO content is below about8 ppm.

In an embodiment, the coating reduces the gas permeability of theplastics to prevent the internal fluid volume from absorbing gasses.This is done to maintain the Dissolved Oxygen level in the sealed watervolume below a certain level. Metallization sputtered coatings rangingbetween 500 and 1500 angstroms work well for this purpose. Desirably theinsides of the plastic housings are coated with 80 microinches of copperfollowed by 10 microinches of nickel. The testing shows that the platingabsolutely reduces the gas permeability of the plastics. The thicknessis not as critical assuming that the atomic radii of the coating metalare smaller than the pores in the plastic. It is believed that the atomsof metal cover and fill the pores.

A temperature sensor may be provided to sense the temperature of thewater in the lower compartment 600. If desired, operation may alteraccording to a sensed temperature, such as by shutting down operation,slowing operation, or increasing cooling.

In an embodiment, the cartridge may be cooled directly by the fluidicsof the main system (FIG. 31). The baffles are removed and the fluid fromthe fluidics system flows directly into the cartridge through an inletport bal seal 620 and out through the outlet port seal 622. Fluid fromthe fluid circulation system floods the cartridge after it is connectedto the upper compartment 510 and bathes the transducer assembly 900 influid. Fluid flow velocity is adjusted to provide the desired coolingtime to bring the cartridge to the desired internal temperature. It mayalso be used to provide additional cooling to reduce skin sensitivity ofa patient being treated (like placing a cold pack on the skin). In thisembodiment the fluid circulation system includes a degas unit to removegas displaced by fluid when the cartridge is initially flooded withfluid. In an embodiment the fluid is water which is filtered anddegassed. A pressure adjustment device or pressure control system may beused to keep the cartridge under pressure if the window is flexible, orsome other component of the cartridge may change that may effect theinternal pressure.

Therapy heads described herein provide a number of benefits. First, alower compartment can be a self-contained unit, without water connectorsor water conduits. Such a lower compartment, or transducer cartridge,does not need to be drained when the lower compartment is replaced.Thus, unlike prior art systems, water is not circulated from the baseunit to the lower compartment, and a particular pressure of water into alower compartment does not have to be maintained.

Additionally, in some embodiments, the lower compartment and thetransducer are integrated into an easily replaceable unit that does notrequire the removal of wires or water or other fluid conduits. By simplyattaching a lower compartment to an upper compartment, a heat transferplate or heat exchanger is attached to a thermoelectric device and thelower compartment is prepared for use.

The transducer assembly 900 used in the lower compartment or cartridge600 is now described. In an embodiment the transducer assembly has acylindrical shell having a transducer mounted in one end of thecylindrical shell, and a mechanical arm and electrical connector mountedin the opposite end of the cylindrical shell. The shell contains a PCBdedicated to run the transducer, and handle any data feedback flow fromthe transducer to any other part of the system 100. The transducer maybe a single element mechanically focused ultrasound transducer aspreviously described in co-pending U.S. patent application Ser. No.12/051,073 entitled “Interchangeable High Intensity Focused UltrasoundTransducer” which is commonly assigned. Alternatively the transducer maybe an annular array, linear array or phased array transducer with thecapability of delivering therapeutic ultrasound.

In another aspect the interface cable 116 has a coaxial cable forpowering, controlling and receiving signals from the individual elementsof an array transducer. Fewer channels in the cable 116 may be used if atransducer array has more than one element tied to a single controlline, allowing all tied elements to be excited simultaneously from thesame command signal.

A transducer assembly for use in the systems described herein may allowfor some variation. A tall stack and a short stack transducer assemblyare provided for. The tall stack transducer possesses the features forinterchanging the transducer in the therapy head. The short stacktransducer is provided for embodiments that may utilize a transducercartridge. It is possible to use the tall stack transducer in atransducer cartridge, however the cartridge becomes elongated, and themass of the transducer on the end of the pivot arm may be problematic asthe transducer is moved in a three dimensioned pivot arc. Firstdescribed are the tall stack transducer assemblies. In an embodiment, atransducer for use with the therapy head is now described (FIG. 36A).The transducer can be similar to one previously described in co-pendingU.S. patent application Ser. No. 12/051,073 entitled InterchangeableHigh Intensity Focused Ultrasound Transducer. In an embodiment, there isa housing 3616 having a substantially cylindrical shape. The housing3616 has a neck down region located near an isolation layer 3634, and alarger diameter near a mechanically focused transducer 3622. Thetransducer side 3620 is open, or has a window so ultrasound energy maybe broadcast out of the housing 3616 unimpeded. The transducer 3622 issecured near the open end 3620, and connects to an interface 3628 via aset of connection pins 3624. The connection pins 3624 are held in placewith a concentric liner 3626 inside the housing 3616. The interface 3628may be a set of connecting wires as previously described, or may includea circuit, PCB, PC(B)A or other hardware component. The interface mayalso have additional electronics, such as a transformer 3642 for tuningthe transducer 3622, a data chip or integrated circuit (IC) 3630 to helpidentify the interchangeable transducer 3610 to the medical system.Additional components are described below.

Behind the transducer 3622, there is a seal 3614 for preventing water oratmosphere from entering the internal compartment of the transducerassembly 3610. Working in conjunction with the seal 3614 is an isolationlayer 3634 for reducing pin corrosion and/or cross talk between theexternal electrical connectors 3640. Note the transducer side 3620 isalso sealed against the outside environment. While the transducer side3620 may be sealed with the transducer 3622 itself and various compoundswhich can be used to prevent leakage, the seal 3614 has one or moreapertures 3650 for the protrusion of the external electrical connectors3640. The apertures 3650 are typically large enough to allow the passageof the electrical connectors 3640. The apertures may rely on aninterference fit to prevent seepage of fluid between the apertures andthe pins, or the use of a sealing agent, or both. The apertures 3650 maybe sealed once the external electrical connectors 3640 are placed usingsolder, epoxy, resin, adhesive or other suitable sealing agents. Amechanical connector 3632 is located on the housing and designed forengagement of a corresponding connection on the medical system socket3638. The mechanical receiving element 3636 and mechanical connector3632 form a transducer-system connection. This connection is typicallyone having high endurance. Repetitive reliability is desirable, but notrequired for the transducer connector 3632, as it is not envisioned thatany one particular transducer will be removed and inserted a largenumber of times.

The design of the transducer connector 3632 and the system sideconnection (receptor) 3636 allow for individual transducers to beinterchanged with the medical system on demand. This allows a singlemedical system to have a great deal of variety in its operational scope.Each new transducer can provide added capability as well as replacementfor worn or out dated parts. In one aspect the mating of the transducer3610 to the system can be accomplished with a low insertion forceconnector 3632 and receptor 3636 combination. Though the insertion forceis low, the connection is robust so the transducer 3610 will be stablewhile mounted in socket 3638. Electrical communication between thesystem and the transducer is maintained regardless of how the socketmight be moved. The socket is attached to the linkage allowing for thetransducer to move as needed by the motor assembly.

In another embodiment, a transducer assembly having a shortened heightmay be used in a transducer cartridge (a short stack transducerassembly). In an aspect of the embodiment, the transducer eliminates thecylindrical housing. Instead, the transducer may be placed into a shorthousing dimensioned just about the size of the transducer itself (FIG.36B). The transducer 6402 has a matching layer 6404 and the transduceris set inside a lower housing 6406. The lower housing 6406 has an innerring shaped cut out dimensioned to match the circumference of thetransducer 6402. The transducer may be secured into the lower housingusing an adhesive compound, or may be welded into place. Alternatively,the transducer may be press fit into the lower housing by a donut shapedsupport 6414 for supporting electrical contacts. A flex circuit 6408 islaid on top of the support 6414 and upper casing 6410 is used to sealthe assembly together. The upper casing 6410 has a raised roof line tomake room for a recess 6412 used to receive a guide arm from the balljoint. The arm may be fitted into the recess using an interference fit,glue or other adhesive to secure the bonding between the arm componentand the upper casing. A locking piece 6420 is used to help secure theupper casing 6410, the flex circuit 6408 and the lower housing 6406together.

In an embodiment, the flex circuit 6508 connects to the transducer 6502using a set of spring loaded electrical pins 6501 _(a-n) (FIG. 36C). Thespring loaded electrical pins (pogo pins) are seated in the donut shapedsupport 6514, and spring tension of the pins provides pressure on thetransducer 6502 to keep the transducer properly seated against the lowersection 6506. The housing also has an upper housing 6510 with a recess6512 for engaging a moving post. The electrical pins 6501 a-n connect toelectrical lands or contacts on the transducer. A matching layer 6504 isprovided on the transducer as well.

An assembly illustration of the short transducer stack is shown in FIG.36D. The lower section 6606 has a lip on the inner circumference so thematching layer 6604, bonded to the transducer 6602, can sit on the lip.A donut shaped support 6614 sits on top of the transducer 6602 andmatching layer 6604 assembly and provides physical support for a set ofelectrical contact pins 6601 _(a-n), which may be spring loaded pins.The electrical contact pins are in electrical communication with theflex circuit 6608 and the transducer 6602. An upper housing 6610 sits ontop of the flex circuit, donut shaped support and lower housing 6606.The upper section 6610 may be bonded to the lower section. A seal orlocking piece 6620 may be used to secure the flex circuit 6608 into theassembly. The flex circuit has an electrical connector 6630 thatprovides electrical connection and communication between the shorttransducer stack and the therapy head. The electrical connector 6630 maybe shaped to fit within the electrical port 638 (FIGS. 29-31A). Thecircular aperture 6640 of the flex circuit may be positioned to fit overthe ball joint 610 and wrap around to connect to the transducer. Theshort stack transducer may be used in place of the transducer assembly900.

In another embodiment, a hybrid stack transducer may be used. The hybridstack transducer combines the space saving features of the short stacktransducer assembly and the socket style interchange between the system(treatment head) and transducer assembly used in the tall stacktransducer assembly. This hybrid stack allows a therapy head to use asmaller volume of coupling fluid since the size of the transducerchamber defined by a removable cap, and the lower end of the treatmenthead, is reduced.

Transducers used in the various transducer assemblies described hereinare typically high intensity focused ultrasound transducers. Focusingmay be achieved by using mechanically focused (curved) transducers, orelectronically steered/focused transducers such as annular arrays,linear arrays and 2D arrays.

The transducer housing may have a metallization layer on the inside ofthe cylindrical housing to prevent gas from seeping from the inside ofthe transducer assembly into the degassed fluid used in the cartridge.Furthermore the transducer housing has a reduced axial length to allowfor greater mobility within the cartridge. Shortening of the stack ofcomponents over the prior art is accomplished by reducing the housing,tightening the space between the components, and may include reducingthe axial height of components such as the tuning transformer or theelectrical connectors. The housing is dimensioned to allow thetransducer to move and pivot within the cartridge as desired withoutgetting tangled up in the cooling system or the side walls.Alternatively an array transducer may be used in the transducerassembly.

Optionally the treatment head 500 as described herein in variousembodiments, may also include a fluid spraying system for distributing acoupling fluid from within the system, onto the body of a patient, priorto treatment by the treatment head. A system possessing the sprayingdevice is now shown in FIGS. 37-44. In one aspect the fluid used in thefluid circulation system 208 is also used as the coupling fluid on thepatient body. The medical ultrasound system 100 has a fluidics system208 including at least one pump and filter set 220, where fluid ispumped into the treatment head 500. The fluid may be used for any of thefunctions and purposes described herein in addition to being used as acoupling solution for a sprayer. A sprayer 588 (FIG. 37) is positionedwithin the upper compartment 510 of the treatment head 500 and is linkedto a manual trigger 514. A user may aim the sprayer 588 at a desiredportion of the patient and spray coupling fluid on to the patient bydepressing the trigger 514. Since the fluid in the fluidics system isunder pressure, the fluid can spray out and cover the desired area atwhich the user aims at.

In one embodiment the fluid consists essentially of water. The water inthe fluidics system is desirably about 99.0% or better pure, andtypically free of large particulate matter. The filter(s) in the pumpand filter set 220 should remove particulate mass and any impurities inthe water down to a predetermined diameter, such as about 0.2 um(microns). Smaller or larger mesh size filters may be used depending onthe type of particulate matter in the water, e.g., a biocide may be usedto prevent bacterial growth enabling a more porous filter, while lack ofany biocide would call for a small pore filter to capture bacteria. Thefluid typically does not contain surfactants. The general use of wateras a coupling solutions, as described in co-pending U.S. patentapplication Ser. No. 11/373419 entitled Method and Apparatus forCoupling a HIFU Transducer to a Skin Surface shows no surfactant isgenerally needed. In one aspect, the water is degassed, filtered,gel-free, and substantially pure.

The exterior of the ultrasound head 500 can be an ergonomic form factorthat is easily handled by an operator. An example of one embodiment isshown in FIG. 37, but the treatment head may take many other forms. Thetreatment head 500 may have cables extending from it and going to thebase unit 130.

In use, the ultrasound head 500 is manually placed into contact with apatient's skin. Ultrasound treatments are administered through theultrasound head 500.

As shown in FIG. 37, an ultrasound head 500 can include a lowercompartment 600, or cartridge, and an upper compartment 510. The uppercompartment 510 is desirably dry and houses wires, cables, a motorassembly, and/or other features for a transducer, which is mounted inthe lower compartment 600. The lower compartment 600 preferably containsa fluid, such as degassed water, used to couple ultrasound energy fromthe transducer to and through a flexible window 602 located near thebottom of the lower compartment.

In operation, a technician can roll the medical ultrasound system 100adjacent to a patient. The technician can grasp and move the treatmenthead 500, wielding it freely except for the cable 116 connecting thetreatment head 500 to the base 130. The ultrasound head 500 is alignedso that the window 602 is in contact with the patient. The display/UI102 may be operated to generate an appropriate treatment or diagnostictest. During use, the transducer mounted in the lower compartment 600generates ultrasound energy, which may be used, for example, for thedestruction of adipose tissue, as described in U.S. PublishedApplication No. 2006/0122509.

The transducer assembly 900 mounted in the lower compartment 600 maytake various different forms, and, in an embodiment, is movable so thatit may focus toward various different locations of the window 602 aspreviously described.

As described in the background section of this document, as well as inthe above incorporated U.S. patent application Ser. No. 11/373,419entitled “Methods and Apparatus For Coupling a HIFU Transducer To a SkinSurface,” a coupling agent or fluid (e.g., water) can be used betweenthe ultrasound head and the skin to reduce or prevent the attenuation orreflection of ultrasound energy emitted by the ultrasound head'stransducer. To this end, to enhance transmissibility between thecartridge 600 and a user's body, a coupling fluid can be applied to theskin surface to moisten the skin in a substantially even manner. Thetransmission window 602 can then be placed on the skin and pressed intothe skin surface slightly to provide contact across the face of theflexible window with the skin surface.

FIG. 38 is a block diagram of (part of) a medical ultrasound system withintegrated controlled dispersion of coupling fluid, in accordance withan embodiment. Medical ultrasound system 100 includes an ultrasound head500. Coupled with the ultrasound head 500 are one or more coupling fluiddispersion devices 582, such as spray nozzles, through which couplingfluid is dispersed. A flow control subsystem 584 is used to control thetransfer of coupling fluid from a coupling fluid source 586 to the oneor more coupling fluid dispersion devices 582.

In an embodiment, the system 100 is configured so that a doctor,technician or other user can control the dispersion of the cooling fluidwhile holding the ultrasound head in his or her hands by using a trigger514 (FIG. 39) positioned on the upper compartment 510, and within easyreach while holding the treatment head 500. By dispersing the coolingfluid distributed by the fluidics system of the base unit, the operatorcan produce a viable coupling fluid without taking their hands off thetherapy head, or being distracted while reaching for an accessory devicefor dispersing a separate coupling fluid. Thus, in an embodiment, thecooling fluid used inside the system, may also be a coupling fluid usedoutside the system. The dispersed fluid is referred to as coupling fluidwhen it is outside (dispersed) the system.

The coupling fluid may be applied by the coupling fluid dispersiondevices 582 by spraying the coupling fluid onto the skin. For example,the one or more coupling fluid dispersion devices 582 can include one ormore spray nozzles configured to disperse a volume of water on apatient's skin as discussed above. The one or more spray nozzles can bepositioned and oriented relative to the ultrasound head so that they canspray around the transducer cartridge to disperse coupling fluid on thepatient's skin that is located under the flexible window when theultrasound head is spaced slightly from the patient. Although a singlespray nozzle can be used, in an embodiment, multiple spray nozzles areused so that each of the spray nozzles need only be positioned andoriented so as to cover a portion of the patient's skin located underthe flexible window.

The one or more fluid dispersion devices 582 can also be configured tointroduce coupling fluid into the space between the flexible window 602and the skin surface so that the coupling fluid may spread out evenly bycapillary action. In such an arrangement, the nozzles are used todisperse a volume of coupling fluid on the patient's skin so the skinsurface is at least lightly wetted. As the coupling fluid is sprayed onthe skin surface, droplets form are deposited on the skin. In one aspectthe droplets remain small and separate from one another so the dropletsdo not pool together and roll off the skin surface. When the cartridge600 is placed on the moistened skin surface, the droplets arecompressed. The droplets collapse and run together to form a thin filmof coupling fluid. The thin film of coupling fluid may be held in placebetween the transducer and the skin by capillary attraction.

In addition to or instead of one or more spray nozzles oriented asdiscussed above, the fluid dispersion device 582 may use various otherfluid introduction approaches. For example, one or more fluid lines maybe positioned and oriented so that discharged coupling fluid isintroduced into the space between the flexible window and the skinsurface. As a further example, coupling fluid may be supplied to aperipheral manifold having multiple discharge ports distributed aroundthe periphery of the flexible window. One or more peripheral sealingmembers can also be used to help retain coupling fluid between theflexible window and the patient's skin.

In another embodiment, if the ultrasound head 500 is held in closeproximity to a skin surface, the coupling fluid may be introduced intothe space between the flexible window 602 and the skin surface, and thecoupling fluid may spread out evenly by capillary action. For example, aspray nozzle can be oriented so as to spray water towards a peripheralgap between the flexible window 602 and the skin surface. Evendistribution may be promoted by gently rocking the ultrasound head overthe skin surface to help push out large air pockets.

The flow control subsystem 584 can include a variety of components. Forexample, the flow control subsystem 584 can include a hand pump or handactuated switch 514 coupled with the ultrasound head or can include afoot pump or foot actuated switch positioned for use while the surgeonof technician is holding the ultrasound head. The flow control subsystemcan be manually actuated, such as by a hand or foot operated pump. Theflow control subsystem 584 can include a combination of one or moreelectrical pumps, control valves, and/or control switches.

Various coupling fluid sources 586 can also be used. For example, acombined coupling/cooling fluid reservoir can be used to hold a quantityof coupling/cooling fluid for subsequent dispersion onto a patient'sskin. A coupling fluid source can also be a fluid supply line, such as awater supply line where water is used as the coupling fluid. As will bediscussed below in more detail, a coupling fluid source can include afluid system, such as a fluid system configured to use water to cool theultrasound head.

FIG. 39 illustrates a medical ultrasound system 100 that includes acoupling fluid reservoir 208 a as the coupling fluid source. Ultrasoundsystem 100 includes a base unit 130 and an ultrasound head 500 having aunigrip handle 202. A coupling fluid reservoir 208 a can be locatedwithin base unit 130 and coupled with one or more coupling fluiddispersion devices via one or more coupling fluid lines 116 f (FIG. 41).A flow control subsystem that includes one or more flow control devices,such as a solenoid valve and/or a fluid pump, can be used to controlfluid communication between the reservoir and the one or more fluiddispersion devices. For example, where the coupling fluid in thereservoir 208 a is pressurized (e.g., at 10 to 20 psig), a valve (e.g.,a solenoid valve) can be used to regulate the dispersion of controlfluid. A cable 116 from the base unit is shown with the fluid lines 116f from the interface cable descending into a fluid controller 707. Fromthe fluid controller 707 one fluid line 709 goes to the sprayer 582.Multiple lines may be used to feed multiple sprayers. Other fluid linesexiting the fluid controller are the fluid input line for a fluid path704 to the cooling device 750. A return line 705 is also shown wherewarm water returns from the cartridge to the fluid circulation circuit700. FIG. 41 also one possible route of the power and coax lines 116t bygoing through the motor assembly and entering the cartridge through thecenter of the control arm 578. Alternatively the power and control linesfor the transducer assembly may go through a separate electricalconnector.

A control switch, such as a momentary switch (i.e., normally open switchwhere the contacts engage only while held in the closed position), canbe used to activate the solenoid valve. A control switch can also beused to activate a pump that transfers coupling fluid from the reservoirto the one or more fluid dispersion devices (e.g., spray nozzles). Acombination of a pump and a solenoid valve can also be used. Manuallyactuated pumps, such as hand or foot actuated pumps, can also be used. Aflow control device can be located inside the reservoir 208 a or alongthe coupling fluid line 116 f.

A control switch can be located for convenient use by an operator of themedical ultrasound system such that the operator does not have to taketheir hands off the handles of the ultrasound head. For example, thecontrol switch, such as momentary switch, can be coupled with one of thehandles so as to be operable by the operator's thumbs. As a furtherexample, a foot activated control switch can also be used. Such a footactivated control switch can be coupled with the base unit directly in aconvenient location, or can be a separate unit that can be positioned bythe operator in a convenient location.

In another embodiment, coupling fluid extracted from a fluid system thathas another function for the device 100 can be sprayed onto the skin foruse as a coupling fluid. For example, water can be extracted from acooling system and sprayed onto the patient's skin for use as a couplingfluid. For example, such a cooling system can be configured to circulatecooling water between a heat exchanger located within the ultrasoundhead and an external heat exchanger. The cooling water can absorb heatfrom the ultrasound head and release the heat at the external heatexchanger. After absorbing heat from the ultrasound head, the coolingwater may be at a temperature where it can be sprayed onto a patient'sskin without causing discomfort (i.e., not too cold and not too hot).The cooling system can be coupled with a supply reservoir or supply lineto replenish the cooling system for any cooling water dispersed. Otherfluid systems may be used.

FIG. 40 is a block diagram of (part of) a medical ultrasound system 100,in accordance with an embodiment, having a fluid system 208 from whichthe coupling fluid can be obtained. Similar to the medical ultrasoundsystem 100 discussed above, the medical ultrasound system 100 includesan ultrasound head 500, one or more coupling fluid dispersion devices582 coupled with the ultrasound head and a flow control subsystem 584that is used to control the transfer of coupling fluid from the fluidsystem 208 to the one or more fluid dispersion devices 582 (FIG. 41).The fluid system 208 can be any fluid system that contains a couplingfluid (e.g., water), such as a cooling system that is configured to usewater to cool the ultrasound head so as to dissipate heat generated bythe ultrasound transducer. The one or more coupling fluid dispersiondevices 582 and the flow control subsystem 584 can include variouscomponents and configurations, such as those discussed above withreference to the medical ultrasound system 100 (shown in FIG. 39).

FIG. 44A is a perspective view of an ultrasound treatment head 500having integrated spray nozzles 582, in accordance with an embodiment.The integrated spray nozzles 582 can be distributed around theultrasound treatment head 500 and oriented so as to disperse couplingfluid as discussed above. While two spray nozzles 582 are shown, one ormore spray nozzles 582 can be used. For example, four spray nozzles canbe used with each side of the ultrasound head 582 having one spraynozzle 582 disposed thereon. A spray nozzle 582 can be positioned andoriented so as to disperse coupling fluid via a spray pattern 70. Asdiscussed above, the one or more spray patterns 70 can be used todisperse and/or introduce coupling fluid on the patient's skin locatedunderneath the flexible window 602 when the flexible window 602 is heldadjacent to the patient's skin. In an embodiment, the one or more spraypatterns 70 are configured so that they will fully cover the area of theskin underneath the flexible window 602 when the flexible window isspaced a predetermined distance from the patient's skin.

FIG. 44B provides an embodiment of aligning the therapy head 500 to gridlines drawn on the patient body, as described below. The therapy headmay project alignment markers via guide lights 4402, 4404 on the patientskin in the form of intersecting lines 4406, 4408, using lasers, LEDlights or other light projecting elements. Such elements are readilyavailable and may be incorporated on to the exterior of the therapy headto produce a guide indicia for the user. The light source may bedirectly presented on to the patient skin or through a reflective device(such as an oscillating reflector sometimes used with a laser to producea visual scan line).

FIG. 42 is a perspective view of an ultrasound treatment head 500 havingone or more spray nozzles 582 disposed within handles 584, in accordancewith an embodiment. A spray nozzle 582 can be disposed in a region of ahandle 584 that is offset from the ultrasound therapy head 500 so thatthe spray pattern 86 can be directed towards the patient's skin locatedunder the flexible window 602 when the ultrasound head is held adjacentto the patient's skin. Such an orientation can help to reduce the amountof movement of the ultrasound head from its position during couplingfluid application to its position during ultrasonic treatment ordiagnostic test. The ultrasound head can be moved into contact with theskin after the coupling fluid has been applied. The one or more spraynozzles 582 can be located and oriented such that the resulting spraypatterns 86 do not impinge upon the surgeon's or technician's handswhile he or she is holding the ultrasonic head by the handles 584.

FIG. 43 is a perspective view of an ultrasound treatment head 500 havingone or more offset spray nozzles 592, in accordance with an embodiment.The one or more spray nozzles 592 can be offset from the ultrasonictreatment head 500, such as by way of one or more conduits 594. As notedabove, with such an offset the one or more spray nozzles 592 can beoriented to result in one or more spray patterns 96 that reduce theamount of movement of the ultrasound head from its position duringcoupling fluid application to its position during the ultrasonictreatment or diagnostic test. The spray conduits may be fixed orretractable.

To align the treatment head 500 on a patient body, a physician can firstmake a pattern of guidelines on the patient skin. The pattern ofguidelines form one or more site areas. Guidelines allow a physician oruser to place the treatment head on to the patient and proceed in anorderly fashion to treat the desired volume of tissue underneath theguidelines. The guidelines described herein are created using one ofseveral guideline templates 800 (FIG. 45). The treatment head 500 caninclude alignment markers either on the cartridge 600 and/or on theupper compartment 510, so the user can align the therapy head 500 withthe guidelines on the patient. The alignment markers can be located onthe sides of the therapy head instead of the corners.

In an aspect of the assembled therapy head, using the features of thesides of the treatment head 600 as the alignment feature of thetreatment head allows a user to treat variable sized areas that are lessthan the foot print of the therapy head on the patient's skin. If acomplete grid is drawn on the patient, then the spacing of the lines ofthe grid do not have to line up with the size of the treatment head face(as long as they are smaller than the treatable area of the treatmenthead if spaces between sites are not desired). In effect the alignmentis about the intersection of the horizontal and vertical lines of thegrid rather than the area encompassed by the lines. This allows for agiven treatment head with its physical treatment head area to not haveto match the treatment area the user may want. Another way to state itis that a given treatment head area (size) can be used with multiplegrid size templates based on the area and shape of the desired treatmentregion. Two examples are shown in FIGS. 46 and 47 with FIG. 47 havingthe grid be the same size as the treatment head, while FIG. 46 has thearea of the site being about ¾ the area of the treatment head. Othervariations are of course possible, but are not diagrammed so as toprevent the application from being prolix.

The grid itself is very quick and easy to draw compared to markingcorners. With lines we end up with Number of Linesdrawn=(rows+1)+(columns+1). With corners we end up with Number ofcorners=(rows+1)*(columns+1). So for example with 4 rows by 5 columns oftreatment grid area we have 11 lines to draw versus 30 corners. Anexample template 800 is shown in FIG. 45. The template 800 includesparallel guidelines 808 that allow a user to draw lines 806 on apatient. As an example, the user may draw one set of parallel lines,rotate the template 800 ninety degrees, and then draw a second set oflines that crosses the first set of lines. The two sets of lines thenform a grid, such as one of the grid patterns shown in FIG. 46 or 47.

If variable site areas and various templates are available to markguidelines, then it can be desirable to minimize the chance of a usermaking an error by marking one size grid on the patient and then settingup the system to treat a different size site. To minimize this chance afeature that the system can read could be embedded into the template.Then after the user marks the patient they would then present thetemplate to the system to have it read the feature, which may be amarked site area, for example, to set up the machine to match thepatient markings This feature could be implemented with an embeddedbarcode 802 on the marking template 800 or with radio frequencyidentification (RFID) type tags embedded into the template. In eithercase the user would “scan” the template into the system to allowentering the treatment screen to set up the system for the correct sitearea.

In use, a user places the template 800 on a patient, marks the gridlines806 in one direction using the guidelines 808, rotates the templateninety degrees, and marks a second set of guidelines 806. Thus, a gridis formed. The user then aligns the side features on the treatment head600 with two crossing lines. The center of the treatment head 600 thusis aligned where two guidelines cross.

If provided, the barcode 802 or other feature may be scanned orotherwise entered into the system after gridlines 806 are applied. Inthis manner, the settings of the treatment head 600 may be matched to agrid.

In an embodiment, the user is able to further define the area oftreatment by using a user defined treatment tool. This embodimentprovides a medical ultrasound system having the base unit with thepreviously described system electronics, user interface and ultrasoundcontrol electronics. The ultrasound therapy head is in electroniccommunication with the base unit, the therapy head has a high intensityfocused ultrasound (HIFU) transducer disposed within it.

The user interface can include a touch screen interface. The touchscreen can detect menu selections, and free hand drawings made eitherusing a stylus or appendage of the user. A coordination operationcoordinates the designs of free hand drawings and provides data to theultrasound control electronics such that a user can define safe or “notsafe” treatment zones through free hand drawings and enable theultrasound control electronics to distinguish safe verse not safetreatment zones during a therapy regiment.

The ultrasound control electronics can prevent the transducer frombroadcasting ultrasound energy into the “not safe” zones by controllingeither the broadcasting of ultrasonic energy by the transducer, or themotor control for moving the transducer. In an embodiment, theultrasound control electronics control a motor drive unit and preventthe motor drive unit from moving the HIFU transducer over the “not safe”treatment zones. In another embodiment, the ultrasound controlelectronics control the operation of the HIFU transducer and prevent theHIFU transducer from broadcasting HIFU energy over the “not safe”treatment zones. In a third embodiment the ultrasound controlelectronics prevent the movement over the no safe zone, and prevent thefiring of the transducer over the “not safe” zones, and selects one orthe other depending on the size and shape of the “not safe” zone so asto select the option most efficient for the system operation. Variationsand/or combinations of these embodiments can be used.

In another embodiment, the system has a scanner for recording lines froma patient's body, the lines defining a treatment area and anon-treatment area. The system can detect through a preprogrammeddetection method in the scanner, which are safe and not safe treatmentzones. This may be achieved by using different colors on the safe versesnot safe treatment areas (e.g. green and red), or using other indiciathe scanner is able to detect and correlate with a preprogrammeddetection method.

FIG. 48 is a simplified block diagram of an exemplary computer system4000 in accordance with embodiments. The computer system typicallyincludes at least one processor 4060 which communicates with a number ofperipheral devices via a bus subsystem 4062. These peripheral devicesmay include a storage subsystem 4064, comprising a memory subsystem 4066and a file storage subsystem 4068, user interface input devices 4070,user interface output devices 4072, and a network interface subsystem4074. Network interface subsystem 4074 provides an interface to acommunication network 4075 for communication with other imaging devices,databases, or the like.

The processor 4060 performs the operation of the computer systems 4000using execution instructions stored in the memory subsystem 4066 inconjunction with any data input from an operator. Such data can, forexample, be input through user interface input devices 4070, such as thegraphical user interface. Thus, processor 4060 can include an executionarea into which execution instructions are loaded from memory. Theseexecution instructions will then cause processor 4060 to send commandsto the computer system 4000, which in turn control the operation of theultrasound control electronics. Although described as a “processor” inthis disclosure and throughout the claims, the functions of theprocessor may be performed by multiple processors in one computer ordistributed over several computers.

User interface input devices 4070 may include a keyboard, pointingdevices such as a mouse, trackball, touch pad, or graphics tablet, ascanner, foot pedals, a joystick, a touch screen incorporated into thedisplay, audio input devices such as voice recognition systems,microphones, and other types of input devices. In general, use of theterm “input device” is intended to include a variety of conventional andproprietary devices and ways to input information into the computersystem. Such input devices will often be used to download a computerexecutable code from a computer network or a tangible storage mediaembodying steps or programming instructions for any of the methods ofthe present invention.

User interface output devices 4072 may include a display subsystem, aprinter, a fax machine, or non-visual displays such as audio outputdevices. The display subsystem may be a cathode ray tube (CRT), aflat-panel device such as a liquid crystal display (LCD), a projectiondevice, or the like. The display subsystem may also provide non-visualdisplay such as via audio output devices. In general, use of the term“output device” is intended to include a variety of conventional andproprietary devices and ways to output information from the computersystem to a user.

Storage subsystem 4064 stores the basic programming and data constructsthat provide the functionality of the various embodiments. For example,database and modules implementing the functionality of embodimentsdescribed herein may be stored in storage subsystem 4064. These softwaremodules are generally executed by processor 4060. In a distributedenvironment, the software modules may be stored in a memory of aplurality of computer systems and executed by processors of theplurality of computer systems. Storage subsystem 4064 typicallycomprises memory subsystem 4066 and file storage subsystem 4068.

Memory subsystem 4066 typically includes a number of memories includinga main random access memory (RAM) 4076 for storage of instructions anddata during program execution and a read only memory (ROM) 4078 in whichfixed instructions are stored. File storage subsystem 4068 providespersistent (non-volatile) storage for program and data files, and mayinclude a hard disk drive, re-writable non-volatile memory chips (suchas Flash memory), a floppy disk drive along with associated removablemedia, a Compact Digital Read Only Memory (CD-ROM) drive, an opticaldrive, DVD, CD-R, CD-RW, or removable media cartridges or disks. One ormore of the drives may be located at remote locations on other connectedcomputers at other sites coupled to the computer system. The databasesand modules implementing the functionality of the present invention mayalso be stored by file storage subsystem 4068. The file storagesubsystem may have directory and file descriptions for accessing thefiles, or it may store data without descriptions and rely on thedatabases and modules of the system to locate the data.

Bus subsystem 4062 provides a mechanism for letting the variouscomponents and subsystems of the computer system communicate with eachother as intended. The various subsystems and components of the computersystem need not be at the same physical location but may be distributedat various locations within a distributed network. Although bussubsystem 4062 is shown schematically as a single bus, alternateembodiments of the bus subsystem may utilize multiple busses.

The computer system 4000 itself can be of varying types including apersonal computer, a portable computer, a workstation, a computerterminal, a network computer, a module in a circuit board, a mainframe,or any other data processing system. Due to the ever-changing nature ofcomputers and networks, the description of the computer system depictedin FIG. 48 is intended only as a specific example for purposes ofillustrating one embodiment. Many other configurations of the computersystem are possible having more or less components than the computersystem depicted in FIG. 48.

FIG. 49 schematically illustrates a plurality of modules 4080 that maycarry out embodiments. The modules 4080 may be software modules,hardware modules, or a combination thereof. If the modules are softwaremodules, the modules will be embodied on a computer readable medium andprocessed by a processor 4060 in any of computer systems of the presentinvention.

A first module is a touch screen interface module 4100. The touch screeninterface module receives data from the touch screen, e.g., the userinterface input device 4070, as described above. In addition, the touchscreen interface module may be configured to receive body data 4102and/or contour/mapping information 4104.

Information from the touch screen interface module is forwarded to atreatment module 4106. The treatment module 4106 generates treatmentinformation and forwards that information to an ultrasound controlmodule 4108, which in turn controls the ultrasound electronics for thedevice.

The modules 4080 are designed so that an operator may enter informationinto a touch screen interface, which is in turn received by the touchscreen interface module 4100. The touch screen can detect menuselections and freehand drawings or other contact made with the touchscreen made using either a stylus or a finger of the user.

For example, in FIG. 50, a display 4110 for a touch screen is shown. Inthe display, menu selections are provided in the form of a treat button4112 and a do not treat button 4114. These menu selections may beprovided on the touch screen 4110 or via another selection device. Inaddition, the selection items may be called something else, such as“safe” and “non-safe” zones or may use some other terminology.

The touch screen interface module utilizes the body data 4102 to displayan image or representation of the body of the user, shown by thereference number 4116 on the touch screen display 4110. In theembodiments shown in the drawings, only a portion of a user's abdomen isshown, but a larger part of the body may be represented.

The touch screen interface module 4100 may access the contour/mappinginformation 4104 and overlay that information on the body image 4116.For example, a grid 4118 may be overlaid over the user. This grid maycorrespond with a grid that is drawn on the patient or projected on thepatient.

In either event, the touch screen display 4110 shows some type ofrepresentation of a patient's body 4116 and provides some mapping orgrid information that permits correlation between the patient's body andintended treatment areas on the body. Scanners, X-ray information,photographs, grid data or other information may be used to coordinatebetween the body data 4102 and the contour/mapping information 4104.

FIG. 51 shows steps for providing treatment information to theultrasound control module 4108 in accordance with embodiments. Beginningstep 4130, an image of the body, such as the image 4116, is displayedfor the user. This display may also include the contour/mappinginformation 4104, such as by displaying the grid 4118.

At step 4132, the system receives user input regarding a desiredtreatment. For example, the user may press the treat button 4112 andthen run his/her finger across a portion of the screen where treatmentis desired. The user may also or alternatively hit the do not treatbutton 4114 and then select some areas for which treatment is notdesired. As an example, the user may select a rib area of a patient fornot having treatment, and an area having a high percentage ofsubcutaneous fat for treatment.

At step 4134, a treatment plan is generated, and that treatment plan issent to the ultrasound control module at 4136. The ultrasound controlmodule may then utilize that information to operate the therapy headand/or ultrasound treatment device accordingly, such as by turning onand off the transducer in accordance with areas selected by the user, orcausing the transducer to avoid non-treatment areas. Selective treatmentof particular areas is described in more detail in the followingparagraphs.

FIG. 52 schematically illustrates modules 4150 for providing variabletreatment to different areas of a user in accordance with embodiments.By “variable,” we mean that treatment may be given to some areas and notothers, and/or more treatment or dosage may be given to some areas thanothers. The treatment may be variable for a single positioning of thetherapy head. Thus, even though the therapy head remains stationary,areas treated while the therapy head may receive varied dosages, or nodosage at all.

A patient data module 4152 provides patient data, such as the body data4102 and/or the contour/mapping information 4104, to a partial sitetreatment module 4154. The partial site treatment module generates atreatment plan and provides that treatment plan to the ultrasoundcontrol module 4156, which in turn controls the ultrasound controlelectronics of the device.

As an example, the therapy head may be designed to sweep over an areasuch as 1 inch by 1 inch, and the partial site treatment module 4154 mayinstruct the transducer to not move over the areas that are indicated asnot having treatment and to move over and provide dosage to the areasindicated as having treatment. As an alternative, the transducer maypass over all areas, and the partial site treatment module 4154 mayinstruct the transducer to broadcast energy over treatment zones, andprevent the broadcast of energy over the areas that are indicated as nothaving treatment.

As an example, as shown in FIG. 53, a treatment site 4160 includes twono treatment zones 4162, 4164, and a treatment zone 4166. As statedabove, as the therapy head is placed over the area 4160, the transducermay either not travel to the no treatment zones 4162, 4164, or notbroadcast in these zones. The therapy head will travel to and treat thetreatment zone 4166.

FIG. 54 shows steps for establishing a partial treatment of an area inaccordance with embodiments. The process starts at 4202, where thepatient is evaluated by a medical professional. The medical professionalmarks boundaries of each planned treatment zone in step 4204. Theseboundaries may be marked on a user or may be provided via the touchscreen interface as described above.

At step 4206, the treatment area is divided into treatment sitesrepresenting locations at which the therapy head will be placed. Thesetreatment sites may represent a number of squares, which may berepresented as a grid on the patient as defined above.

At step 4208, a determination is made whether all sites have beentreated. If so, the process ends. If not, the process branches to step4210, where a determination is made whether all of the next site istreated with a single dose level. If so, the process branches to step4214, where the next site is treated. The process then branches back tostep 4208. If all of the next site is not treated at one dose; i.e.,part of it is treated and part of it is not, then step 4210 branches tostep 4212, where partial site treatment is conducted, such as describedabove with respect to FIGS. 52 and 53. The process then branches back tostep 4208.

It can be understood that the process described above may also be usedto treat some places in the site more than others. For example, in thesite 4160 shown in FIG. 53, one or more of the regions 4162, 4164,and/or 4166 may have a single dose of energy, whereas others may havetwo or more doses, or the dosage power may vary over boundaries. Ineither event, the partial site treatment module 4154 may provideappropriate instructions to the ultrasound control module 4156.

FIG. 55 shows a method for partial site treatment in accordance withembodiments. Beginning at step 4232, based on the boundaries in thetreatment area (i.e., the boundaries defined for the entire patienttreatment, not just for the particular therapy head site location), theboundaries are determined for a therapy head site. This is done viasteps 4234 and 4236, where the boundaries are interactively definedwithin the site, and then the boundaries are updated and displayedwithin the site. The interactive process may occur, for example, via thetouch screen 4110. These boundaries form the regions within the site,such as is defined with respect to FIG. 53. At steps 4238 and 4240, thedosages within the regions defined by the boundaries are defined. Thisprocess may be done at the same time as establishing the boundaries.These dosages are interactively defined in step 4238 and updated anddisplayed in step 4240. At step 4242, the treatment is activated. Theselected treatment occurs at step 4244.

FIG. 56 shows a method for providing selective treatment at a site inaccordance with embodiments. In the methods shown in FIG. 56, thetransducer moves over all locations under the therapy head, but thedosage is varied at locations, either turning the transducer off and on,or varying the dosage as desired. Beginning at step 4262, adetermination is made at what points in a scanning pattern boundarieswould be crossed. That is, at what points would boundaries betweentreatment and no treatment areas be crossed (or, as described above,varied dosage level boundaries crossed).

At step 4264, the transducer moves through the site in its normalscanning pattern (i.e., as if the entire site were to be treated). Atstep 4266, a determination is made whether the site is complete. If yes,the process is finished. If no, then a determination is made in step4268 whether a boundary has been crossed. If not, the process branchesback to step 4264, where the transducer continues to move through thesite. If a boundary is crossed, step 4268 branches to step 4270, wherethe dosage from the transducer is adjusted (e.g., turned off or on, orincreased or decreased, as discussed above) and the process thenbranches back to step 4264, where the transducer continues to scan thesite.

FIG. 57 shows another method for selective treatment at a therapy headsite in accordance with embodiments. In the methods shown in FIG. 57,the scanning pattern is varied so as to provide selective treatment.Thus, if an area is not to be treated, the transducer can skip thatarea. Beginning at step 4292, a scan pattern is created for each dosageregion in the site. At step 4294, the dosage and pattern for the nextregion is set. The transducer moves through the region in a scanningpattern for that region at step 4296. At step 4298, a determination ismade whether the site is complete. If yes, then the process is done. Ifno, then determination is made at step 4300 whether the region iscomplete. If no, then the process branches back to step 4296, and ifyes, then the process branches back to step 4294. The process continuesuntil the site is complete.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, a certain illustrated embodiment thereof isshown in the drawings and has been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

What is claimed is:
 1. A liquid degas system comprising: a reservoir; aventilation chamber within the reservoir; a conduit located to receive agassed liquid from the reservoir and pass the liquid to a bottom of theventilation chamber, said conduit having a flow restriction therein; apump positioned to flow gassed liquid from the reservoir and through theflow restriction in the conduit to produce a degassed liquid and a gaswhich are released to the bottom of the ventilation chamber; a gas venton the top of the ventilation chamber, said vent having an exit portdisposed in the reservoir; and an outlet which receives degassed liquidfrom the bottom of the ventilation chamber and delivers the degassedliquid out of the ventilation chamber and reservoir.
 2. The system as inclaim 1, further comprising a distribution manifold within theventilation chamber, said manifold receiving the degassed liquid and gasfrom the conduit and distributing such mixture throughout theventilation chamber.
 3. The system as in claim 2, wherein thedistribution manifold includes side walls and a top having orificesformed therethrough.
 4. The system as in claim 1, wherein the gas ventcomprises a vent conduit having the exit port at a level below the topof the ventilation chamber.
 5. The system as in claim 1, wherein thepump is positioned between the flow restriction and the ventilationchamber to draw liquid through the flow restriction.
 6. The system ofclaim 5, wherein the pump draws a negative pressure in the duct betweenthe flow restriction device and the pump in the range from about 1 PSIto 2.5 PSI absolute.
 7. The system of claim 1, further comprising: anenclosure containing the liquid degas system; a cable having a proximalend and distal end, the proximal end connected to the enclosure; and anultrasound therapy head connected to the distal end of the cable whereina liquid circuit extends from the outlet through the cable into thetherapy head.
 8. A method of degassing a liquid, said method comprising:maintaining a gassed liquid in a reservoir; drawing the gassed liquidfrom the reservoir through a flow restrictor to form a mixture ofdegassed liquid and gas; passing the mixture of degassed liquid and gasinto a ventilation chamber within the reservoir, wherein said mixtureseparates into a gas portion which rises to the top of the chamber and adegassed liquid portion which falls to a bottom of the chamber; ventingthe gas from the top of the ventilation chamber into the gassed liquidin the reservoir; and removing the degassed liquid portion from thebottom of the ventilation chamber.
 9. The method as in claim 8, furthercomprising circulating the degassed liquid from the bottom of theventilation chamber through a liquid circuit where it absorbs gas tobecome a gassed liquid and returning the gassed liquid to the reservoir.10. The method as in claim 9, wherein the liquid circuit comprises atherapy head having an ultrasound transducer therein.
 11. The method asin claim 10, wherein the liquid circuit further comprises a heatexchanger to cool the degassed liquid before it enters the therapy head.12. The method of claim 8, further comprising passing the mixture ofdegassed liquid and gas through a distributor manifold having aplurality of orifices which create a positive pressure and restrict theflow rate of the degassed liquid.